The Microbiome Connection Part 3

The Microbiome Connection Part 3: by Mark A. Pimentel

Food poisoning can also disrupt your microbiome and cause IBS symptoms. To minimize your risk of food poisoning, follow these tips: Avoid eating raw foods, such as salads (especially at a salad bar) or raw fish, including sushi. Always heat your food thoroughly. Don’t eat foods that are left at room temperature for a prolonged amount of time (4 or more hours). Avoid eating from street vendors or food trucks, whose sanitation is usually different from that in a restaurant. Food may be unrefrigerated all day and thus be exposed to microorganisms that can cause food poisoning. Avoid eating uncooked vegetables as they are often sprayed or washed with local water. Cook the vegetables and serve them hot. Drink bottled or filtered water rather than tap water, and use bottled water to brush your teeth. Avoid the use of ice cubes, which are likely made from local water. When you bathe or shower, avoid getting water in your mouth. Eat at restaurants that have a reputation for cleanliness and avoid those with code violations. If you eat poultry that’s been frozen, be sure to thaw it fully before cooking it to avoid Salmonella and Campylobacter food poisoning. For the same reason, avoid eating raw eggs. At home, wash all fruits and vegetables thoroughly before eating. Use a non-toxic food detergent, which you may find at your local health food store. Peel the skins off fruit before eating. Wash or sanitize your hands before eating. In hotel rooms, use disposable cups instead of reusable glass or porcelain cups. In some hotels reusable cups are only rinsed rather than properly washed. If you plan to travel to an area that is high-risk for food poisoning, you may want to consider taking half of a rifaximin pill with every meal during your trip, although this is not an FDA-approved treatment. If you’re staying at a rental home or bed-and-breakfast, take further precautions: Clean the countertops. Clean all chopping boards, especially if they’re made of wood. Use separate chopping boards for meat and vegetables. Wash all sponges in the dishwasher. Sponges are known to carry tons of bacteria. To keep food from spoiling quickly, make sure the refrigerator is working properly. Pay attention to expiration dates on the food you buy. Expired food is more likely to contain microorganisms that lead to food poisoning. Let’s talk about our number 2: SIBO. SIBO occurs when there are greater than 1000 bacteria per milliliter (>103/mL) in the small intestine. In SIBO, this excessive quantity of bacteria is not an infection, but rather an over-colonization of specific bacteria in an area where they don’t belong. The bacteria aren’t invading or attacking you; they are your own resident bacteria. SIBO is, in effect, a phenomenon of bacteria dislocated from your large intestine to your small intestine. As the gut descends, the bacteria level varies. Your mouth contains millions of bacteria, but there are less than 100 bacteria per mL in your stomach. (We assume that the high acidity of the stomach kills many of the bacteria.) In the small intestine, the quantity of resident bacteria increases, but there are usually less than 1000 per mL. What causes SIBO symptoms? When food you’ve eaten makes its way into the small intestine to be absorbed, it’s broken down into small pieces and then digested. If you have more bacteria than normal, the bacteria consume the food before you digest it. When the bacteria digest and ferment the food, they produce various gasses: hydrogen, methane, hydrogen sulfide, and carbon dioxide. The excessive amount of gas leads to inflation —like a balloon—of the small intestine. The small intestine, which mostly deals with liquids or solids, isn’t equipped to deal with excess gas. When it fills with gas, it tries to move it forward. But unlike liquids or solids, gas can’t be easily moved, and it becomes trapped in the small intestine. That’s when you feel bloated and your belly may distend. You can’t get rid of the gas because the small intestine is incapable of pushing it forward, whereas when you have gas in the stomach, it can be relieved by belching. Excessive gas in the colon is passed as flatulence. There are, however, mechanisms for gas in the small intestine to disappear. Slowly, the gas is absorbed through your bowel wall into the blood circulation. When the blood passes through the lungs, gasses are released and you breathe them out. That’s why if you have SIBO, you often wake up with a flat belly because you haven’t produced any gas overnight and the gas you have in your bowel has been absorbed into your circulation. Also, the housekeeper waves are active at night while you are fasting, and the waves push the remnants of food toward the colon, thus limiting the amount of food left for the microorganisms to ferment in the small intestine. When you start eating again in the morning, your symptoms return and become worse throughout the day.  The Causes of SIBO STAGNATION: Bacteria don’t build up magically without cause. Think of the colon as a swamp with slow-moving water and the small intestine as a fast-moving river. The most common cause of stagnation is a lack or impairment of cleaning waves in the gut, which occur every 90 to 120 minutes when you aren’t eating. During the fasting state, these waves strip out debris in the gut after a meal. The salad you had for dinner last night has to be cleaned out so that your gastrointestinal tract is ready for breakfast in the morning. WEIGHT-LOSS SURGERY: Bypass weight-loss surgery can also lead to SIBO. One-third of American adults are obese, so weight-loss surgery—or bariatric surgery—is more popular than ever. One of the most common types of weight-loss surgery is Roux-en-Y, known as gastric bypass. This nonreversible surgery works by decreasing the amount of food you can eat at one sitting and by reducing absorption of nutrients. Typically, the surgeon cuts across the top of your stomach and makes it into a pouch about the size of a walnut, drastically reducing the amount of food you can hold in your stomach. The surgeon then cuts a loop of the small intestine and sews it directly onto the pouch. Food bypasses most of your stomach and the first section of your small intestine, thus entering directly into the middle part of your small intestine. This loop of bypassed small intestine is blind to food or liquid passing through it. Because nothing flows through those three feet of the small intestine, they can become stagnant. There are no effective cleansing waves flowing through it, however bacteria can still grow—or overgrow—in it, leading to SIBO. Inflammatory diseases, such as Crohn’s disease and severe celiac disease, cause significant inflammation in the wall of the small intestine and inhibit bowel clearance. They can also lead to strictures (abnormal narrowing) that alter the gut as well and, again, lead to SIBO. Diabetes is one of the most common diseases that affect gut motility. This metabolic disorder causes your blood glucose (blood sugar) levels to be too high. One of the long-term consequences and the most common complication of diabetes is peripheral neuropathy, or nerve damage caused by chronically high blood sugar levels. This leads to numbness, loss of sensation, and sometimes pain in your feet, legs, or hands. The nerve damage can affect the nerves in the gut as well, leading to abnormal gut motility and subsequent SIBO. DRUGS: Narcotics can slow down the gut and lead to SIBO. The opioid crisis has led to many SIBO cases because narcotics precipitate bacterial overgrowth. The main effect of narcotics is pain relief, but they dramatically slow down the gut and cause classic constipation, as well as heartburn, gastric reflux, abdominal discomfort, and opioid-induced bowel dysfunction, which is a potentially debilitating side effect of chronic opioid use. Fortunately, we have drugs, such as methylnaltrexone, that can specifically negate the bad effects of narcotics on the gut without taking away the pain-killing effects. Anticholinergics used in urology and gastroenterology to decrease symptoms of urinary infrequency or abdominal cramps work by slowing down the gut to alleviate cramps, which, in turn, affects gut motility. Antacids used to neutralize stomach acid to reduce heartburn may decrease the amount of acid in the stomach, decreasing its efficacy in killing bacteria and potentially leading to more bacterial overgrowth. However, the link between acid-suppressing agents and SIBO is not yet clear. We have reported in a large study that stronger acid suppressing medicines—called proton pump inhibitors—are not associated with bacterial overgrowth or any drastic change in the small intestine microbiome. Although proton pump inhibitors significantly affect the acidity of the stomach, they don’t affect the acidity of the small intestine. If your small intestine is healthy, it can balance the effects of proton pump inhibitors without an overgrowth of bacteria. The primary—and easiest—method of diagnosing SIBO is through a breath test. Gut bacteria can produce carbon dioxide as a fermentation product, just like the bubbles in beer. We humans also produce carbon dioxide, so looking for this gas won’t reveal whether the carbon dioxide is made by bacteria or by us. Bacteria and other microorganisms also produce hydrogen and methane, which is unique to them. When we find these gasses in the breath, we know they come exclusively from microorganisms in the gut that have migrated to the breath.

The Microbiome Connection Part 2

The Microbiome Connection Part 2: by Mark A. Pimentel

Digestion requires constant, synchronized contractions of the various gut muscles to control the movement of food through the gastrointestinal tract. These contractions are known as gut motility. Motility problems can develop when the nerves and/or muscles of the gut are not working properly. Abnormal gut motility can lead to bloating, pain, nausea, and diarrhea or constipation, all of the symptoms related to IBS. When gut motility is working well, during the feeding phase the stomach pushes food mixed with acid toward the pylorus, which senses whether the food is broken down enough to allow it to pass into the small intestine. The small intestine is responsible for mixing and spreading the food to maximize protein and sugar break down, as well as mixing fats and bile into little packages during the feeding phase. When the stomach is full of food and distends, the gastrocolic reflex signals the colon to empty, and the colon pushes stool forward. This is why you occasionally have a bowel movement after eating. The reflex also functions to drive the existing intestinal contents through the gastrointestinal tract to help make way for ingested food. The very act of eating can provoke an overreaction of this reflex in some patients with IBS because of their heightened visceral (intestinal) sensitivity. IBS patients tend to describe the experience of pain within the internal organs (the viscera) at a more intense level than normal, leading to the classic symptoms of IBS. The Fasting Phase After the feeding phase ends, the fasting phase begins. Initially the small bowel doesn’t move or only partially moves such that food gets mixed with enzymes in the small intestine. When digestion is complete, housekeeper cleaning waves (also known as migrating motor complexes phase 3) begin and occur every 90 to 120 minutes for a few minutes at a time. The waves move into the small intestine, where they push the remnants of undigested food, bowel secretions, and excess bacteria forward and dump them into the large intestine. The housekeeper function is one of the keys to understanding IBS. For those who are significantly affected by IBS, the housekeeping role malfunctions and “cleaning” of the bowel is impaired; that is, more bacteria accumulate and grow on the debris in the small intestine, producing many side-products—including gas—which leads to bloating, abdominal distension, diarrhea, or constipation. Motility issues can also stem from problems in gut immunity. Your gut has millions of immune cells—more immune cells than anywhere else in your body. The intestinal immune system encounters more antigens—toxins or other foreign substances that induce an immune response—than any other part of the body. That’s because you’re bringing the outside world into your body by eating. You need defenses. Your gut is also the home of the body’s largest microbiome. This microbiome ideally contains a healthy balance of bacteria, as well as fungi, parasites, viruses, and archaea (single-cell organisms, including methanogens, which produce methane gas as a metabolic by-product). These microbes live throughout your digestive system. They live in your mouth and in your intestines, and they have different functions and interactions. If the delicate balance of the microbiome is upset, for example, by food poisoning or excessive bacteria in the small intestine, you may develop IBS. Everything you eat affects your microbiome. Various dietary patterns shape the microbiome and can lead to differences in immunity. A more diverse gut microbiome can lead to a more robust, adaptable immune system. The wide variety of protective bacterial strains already found in your gut were partly passed down from your mother at childbirth. Antibiotics, diet, infections, and other factors may reduce their abundance, but these bacteria are usually not completely eradicated. It’s important to nurture and reinforce a healthy gut microbiome. There are numerous beneficial functions of a healthy gut microbiome. Gut microbes modulate other bacteria and facilitate the extraction and fermentation of dietary fibers. They generate heat and can change your basal metabolic rate. They also produce vitamins and are mediators of peptides (small proteins), which play key roles in regulating the activities of other molecules, modulating immune responses, and influencing other bacteria. The way in which the microbiome interacts with the body is important to gastrointestinal function. The human microbiome produces some of the same compounds that are produced by human cells. For example, the microbiome secretes serotonin, a mood chemical, leading some researchers to believe that bacteria can influence mood as well as insulin-like proteins and other chemicals that allow your body to function. Serotonin has a neuromodulating effect that causes nerves to fire and modulate gut function. A disruption in the microbiome may increase serotonin levels and can lead to diarrhea, or, if hormone production is reduced, constipation. Your microbiome contains five specific components that promote health and ward off disease. Diversity of bacteria and fungi in the gut. In the large microbiome city of your gut, the more diverse the population, the healthier it is. You wouldn’t want a city filled only with doctors or lawyers, for example. Distribution of bacteria and fungi. Differing types of bacteria are positioned strategically throughout the gut. For example, the colon bacteria are different from the small intestine bacteria because accumulation of bacteria from the colon in the small intestine leads to SIBO and its associated symptoms. Number and composition of bacteria. In the scientific literature this is described as relative or absolute abundance. With thousands of varieties of bacteria, your microbiome city has occupants with characteristics that allow them to complete their specific tasks. The number of each microbe is proportional to its roles and functions. Five plumbers would not be enough for a big city. You need the right amount of each bacterium for functioning harmony. Products of bacteria. The many inhabitants of your microbiome city produce a wide variety of products, some of which are good and others are bad. For example, some bacteria have properties that reduce inflammation in the gut and others promote normal motility. On the other hand, gas and other chemicals produced by bacteria in the microbiome can contribute to the symptoms of IBS. It’s important to understand that bacteria are not “good” or “bad” all the time. It’s more about maintaining balance in your microbiome. Resiliency. If you look at your microbiome after taking antibiotics, you’ll likely find that the numbers of microorganisms are drastically reduced. Two weeks later, the bacteria repopulate your gut and the microbiome snaps back to normal. That’s resiliency. But if you continue to take courses antibiotics, they can adversely affect your microbiome. The microbiome is like an elastic band that becomes a little less stretchy every time you pull on it. It may not snap back all the way if you take too many antibiotics. Food additives can also disrupt the microbiome. For example, emulsifiers are added to food to make it creamy, or sodium benzoate is added to reduce fungal growth and preserve shelf life. These additives make food more appealing, but they have the potential to disrupt the microbiome. An emulsifier such as polysorbate 80 disrupts mucous membranes and, in effect, emulsifies your microbiome too. And sodium benzoate kills fungi that are supposed to be in the microbiome.

The Microbiome Connection Part 1

The Microbiome Connection Part 1: by Mark A. Pimentel

In this book, the author explains how the microbiome of the gut can impact gut illnesses, two of which are highlighted in this blog: IBS and SIBO. Gastrointestinal illnesses are common and it’s important that they are talked about. Let’s start with IBS.

If you’ve had the following symptoms for three or more months, you have IBS: abdominal pain and/or discomfort, diarrhea, constipation, bloating, gas, urgency, incomplete evacuation, relief or worsening of pain with defecation, brain fog, early satiety (a sense of fullness without having eaten much), or both diarrhea and constipation. The last symptoms, diarrhea and constipation, may strike you as impossible, but they have now been classified as one of the three distinct types of IBS. First, there is IBS-C, meaning IBS with constipation. This type is found in 35 percent of patients. Second, there is IBS-D, which is IBS with diarrhea, found in 40 percent of patients. Third is IBS-M (mixed type), which is IBS with alternating bouts of diarrhea and constipation, found in 23 percent of patients. In this category, many patients don’t know whether they will be hit with diarrhea or constipation. During the course of one day, they might be constipated in the morning, but have diarrhea in the afternoon. And within one bowel movement, their stool may be hard at the beginning and watery at the end. So, we now consider IBS-D and IBS-M as one type of IBS disease—Non-constipation IBS—and IBS-C is possibly a different disease, Constipation IBS. Let’s talk about your digestive system. The first point of contact with the digestive system is your mouth, where food begins the journey of digestion. When you think about eating, your brain tells your gut, “Get ready, food is coming.” This turns on the production of saliva, which contains enzymes to begin the breakdown of food. At the same time, the brain sends signals to your stomach and to the colon via the vagus nerve. The signals flip a switch to convert the digestive system from fasting state (“cleaning mode”) to feeding state (“grinding and digesting mode”). The vagus nerve signals also ramp up the pancreas to secrete digestive juices and insulin, the stomach to produce more acid, and the gallbladder to squeeze out bile to help liquify fats and add more blood flow to the gut to gather up nutrients. When you take your first bite of food, the vagus nerve in your brain is excited, and as you swallow it becomes even more excited. By the time the food reaches your stomach, it’s really excited. The brain signals increase in intensity as the food moves closer to the small intestine, where absorption occurs. Remember, the gut has two modes: feeding (digestion) and fasting (cleaning). Two to four hours after you eat and digest a meal, the feeding mode turns off and fasting mode begins. It takes about two hours to digest carbohydrates, and about four hours to digest heavy fatty food or high- protein food. During the fasting mode, waves of electrical activity induce the gut to sweep residual undigested material through the digestive tract. This “housekeeping” role is known as the migrating motor complex. Most often, but not always, this procedure begins in the stomach. The oblong-shaped pancreas is located behind the stomach in the upper left abdomen. It converts food and other nutrients into fuel for the body, and produces pancreatic juice that enters the duodenum of the small intestine. The digestive enzymes secreted by the pancreas help break down proteins, carbohydrates, and fats. The pancreas also produces the hormones insulin and glucagon to help regulate blood sugar. Finally, the pancreas secretes bicarbonate that neutralizes the stomach acid. A balanced pH in the small bowel is crucial for the function of mucosal cells and digestive enzymes. The liver, the largest solid organ in the body, is found in the upper right quadrant of your midsection, just above the colon. It plays an important role in the body’s immune system, as it is the epicenter of detoxification: it will detoxify any toxin it encounters. Alcohol is the most well-known toxin broken down—or metabolized—by the liver. The liver also produces bile acids—the yellowish-brown enzymes that eliminate cholesterol from the body and aid in gut motility for digestion and absorption of fats in the small intestine. Bile acids also contribute to the color of your bowel movements. The gallbladder is a pear-shaped, hollow organ that sits just beneath the liver. In between meals, during the fasting phase, the gallbladder processes, stores, and concentrates bile from the liver. When the gut needs bile, the gallbladder squeezes the right amount out to help digest fats and other components. Once in the gut, some of the bile gets reabsorbed into the blood from the ileum, the last section of the small intestine, and recycles back into the liver. If your gallbladder is removed or is not functioning properly, bile will flow straight from the liver into the small intestine and eventually to the colon, often resulting in diarrhea. It’s important to note that when bacteria encounter bile, they convert it to toxic bile acids (such as deoxycholic acid and lithocholic acid), which are believed to cause diarrhea. This is known as bile acid diarrhea (BAD) and is different from SIBO, but it’s worse when SIBO is present. One of the main causes of bile acid diarrhea is SIBO.

Part 6: More on Body Image, Bloating, Constipation, and Binge Eating

Part 6: More on Body Image, Bloating, Constipation, and Binge Eating

Based on the book "The Science of Nutrition" by Rhiannon Lambert

WHAT IS A DETOX diet AND DETOX TEA? "Detox" is a buzzword in the diet industry. Many products and diet plans promise to rid the body of toxins, help you lose weight, and even reduce cellulite. But detoxes are unnecessary, because your body has a highly effective detoxification system of its own. The truth is, we don’t need to “cleanse” or detox ourselves at all, and following this sort of diet will not have this desired effect. The idea of feeling clean after a detox diet is what spurs dieters to embark repeatedly on expensive and immensely restrictive detox diets. We come into contact with environmental toxins every single day in the air we breathe and the food we eat, for instance. The body is a wonderful organism, which, through the action of the liver, effectively removes toxins and waste products that make it into the body system. Breakfast appears to be especially important when maintaining a healthy weight. Research suggests that controlling food intake across the day is more manageable on a full stomach in the morning—people who eat breakfast appear to be more likely to maintain weight loss in the long term. MENOPAUSE For most women, menopause is a natural aging process during which they lose their period due to declining estrogen levels. Plant compounds called phytoestrogens may help ease hot flashes and night sweats, the most common symptoms. So far, research has focused on one type—isoflavones—found in soybeans and soy-based foods and drinks. WHY DO I FEEL BLOATED? Bloating is the sensation associated with gas in our gut, when your abdomen feels swollen and is commonly distended. It can make us feel uncomfortably full and is sometimes accompanied by pain, flatulence, and nausea. Even in a “fasted” state, our gastrointestinal tract contains gases, which increase after eating due to swallowing air and gases produced during digestion. But it is normal for our stomachs to distend when we eat a meal—they are not supposed to remain flat! WHY AM I CONSTIPATED? Constipation can be frustrating and sometimes painful, resulting in a lot of straining and hard poop. Slow transit constipation occurs when your stool takes such a long time to get through the large intestine, much of its water content is absorbed and it turns hard and dry. Evacuation disorder comes down to the final push to excrete the stool, when coordination of the muscles involved is poor. This could have been a result of childhood toilet habits or be a structural problem of your biology. • Constipation-predominant irritable bowel syndrome is a type of IBS mostly owed to constipation. HOW CAN I STOP BINGE EATING? Binge eating is often explained as eating when we’re not hungry or overeating to provide a temporary distraction from something painful. But the relationship between food and mood goes far beyond that specific moment. Emotional eating is often a way of compensating for a lack of coping skills. And for some, this pattern can become a compulsion. It’s important to note that binge-eating disorder is a serious mental illness where people who eat large quantities of food can feel like they are out of control, which can be incredibly distressing. Binges can leave the individual feeling disconnected from what they’re doing during a binge. They can even forget what they have eaten afterward. Everyone is an emotional eater to some degree. Stress, boredom, anxiety, or sleep-deprivation can make us want to eat more of different foods (or not eat). The problem occurs when our emotions rule how we eat. If we overeat in response to something difficult or painful, we can get caught in the binge-restrict cycle. A binge is followed by guilt, even shame and embarrassment, which can cause an individual to restrict their food intake to compensate. Restriction triggers obsessive thoughts of food and so the cycle begins again. If you can spend time developing new coping strategies for emotional issues, it may help you get to the core of what is really going on and beat the binge-restrict cycle. The binge-restrict cycle can happen to anybody, not just those with eating disorders. If you ever find yourself stuck in the binge-restrict cycle, think about the following: SELF-WORTH Be prepared to work on yourself. Analyze your expectations and values and learn to grow your self-worth and self-esteem. Seek the help of a professional therapist if necessary. FOOD DIARY Work on a food–mood diary. Eat three balanced meals a day and two to three snacks; enough to maintain your body weight—you need to get out of the binge-restrict cycle before trying to lose weight. FEELINGS Understand your feelings. What is your eating style? Are there a lot of rules? Feelings of guilt or sadness? How do you feel if you break one of your rules, and how do you respond? TRIGGERS Identify your triggers. See whether you can recognize yourself in any of the common binge eating triggers below and think about how these states might affect you throughout your day: ANGER | ANXIETY | WORRY | FEAR DEPRESSION | NEGATIVITY | BOREDOM GUILT | SHAME. NEGATIVE THOUGHTS Challenge negative thoughts. Consider naming that inner critic inside your head. You may be surprised to find that you are bullying yourself— a sign that some self-soothing is required. KINDNESS Be kind to yourself. Remember that your body needs food for fuel. If your body is receiving the nutrition it needs, you are less likely to suffer from ill health. You deserve to eat and enjoy food. People with eating disorders use disordered eating as a way of coping with difficult situations or feelings. This behavior can include limiting food intake; eating very large quantities of food at once; getting rid of eaten food through unhealthy means (e.g., vomiting, misusing laxatives, fasting, or exercising excessively); or a combination of these. There’s no single cause, and sufferers might not have all the symptoms of any one eating disorder. Many people are diagnosed with “other specified feeding or eating disorder” (OSFED), which means their symptoms don’t exactly match what doctors check for to diagnose binge-eating disorder, anorexia, or bulimia, but that doesn’t mean that it’s not still very serious. Recognizing the symptoms of eating disorders and knowing they manifest differently from person to person, which can make them tricky to spot. Here are some signs to look out for: BEHAVIORAL SIGNS • Spending a lot of time worrying about your weight and body shape • Avoiding socializing when you think food will be involved • Eating very little food• Making yourself vomit or taking laxatives after you eat • Exercising too much • Having very strict habits or routines around food • Changes in your mood, such as being withdrawn, anxious, or depressed PHYSICAL SIGNS • Feeling cold, tired, or dizzy • Pains, tingling, or numbness in your arms and legs (poor circulation) • Racing heartbeat, fainting, or feeling faint • Problems with your digestion, such as bloating, constipation, or diarrhea • Your weight being very high or very low for someone of your age and height • Not getting your period.

Part 5: Nutrition and Exercise, Body Image

Part 5: Nutrition and Exercise, Body Image

Based off the book "The Science of Nutrition" by Rhiannon Lambert

What do you eat before exercising? The consensus is to eat a meal 2–4 hours before working out, where possible. An ideal pre workout meal is mainly carbohydrate with some protein and a little fat, for example, salmon, white rice, and vegetables roasted in olive oil. If you train early and don’t have the time or appetite, try a more carb-heavy meal the night before. If you’re exercising sooner, or need to top off, a snack (like toast and honey or fruit salad) 1–2 hours beforehand gives a burst of energy for fuel and is quickly absorbed. With under an hour, stick to liquids like smoothies or sports drinks. Experiment to find the optimal timing for your activity, schedule, and digestion. During exercise: Water should suffice for 45–75-minute sessions. After an hour, you may want to consume around 30g of carbs per hour for two hours, increasing to 60g per hour for the next 2–2.5 hours. Gels and sports drinks can help maintain blood sugar levels but can also contribute to stomach upset during endurance activities like distance running; practice what works for you. Carb–protein balance: Recovery foods should contain quality carbohydrates to replenish glycogen and fluid and electrolytes to rehydrate effectively. In addition, combining a small amount of protein with carbs post workout has been shown to more effectively promote glycogen recovery than carbohydrates alone. If your training is mainly strength based, or if you’re training at a high intensity, there is evidence that adding 15g–25g of protein to a post workout meal or snack can reduce muscle soreness and promote muscle repair. Otherwise, follow your food preferences, appetite, and what sits comfortably in your stomach after exercise, and eat when you feel hungry. IS IT GOOD TO BE SLIM? ‘‘Slim’’ is just one of many cultural constructs about how our bodies should look. But achieving these ideals and being a healthy weight aren’t necessarily related. Body size and shape aren’t always the best indicator of health. Someone who eats a less healthy diet and does little exercise may be genetically predetermined to have less body fat than someone in a larger body leading a healthier lifestyle. Based on current evidence, weight loss can be maintained, but a gradual process is more effective. Losing a pound or two a week allows your body to adapt and is sustainable in the long run. As babies, we are in tune with our body’s hunger signals and eat only what we need, but as we age, we’re surrounded by messaging and social pressures around food and lose this innate ability. The complex psychology surrounding our relationship with food undoubtedly plays a role in the failure of diets and can be the biggest barrier to weight loss. Research shows that restrained eaters experience more intense food cravings, heightened emotions surrounding food, and greater preoccupation with it. Likewise, categorizing foods as “good” or “bad” creates a restrictive mindset that increases food cravings and, in turn, the risk of overeating these foods when they are available. Labeling foods as treats implies they can be eaten only once earned, which increases desire. Goal setting can also have detrimental psychological effects, as veering “off plan” can prompt feelings of failure and guilt and subsequent overeating. SHOULD I COUNT CALORIES? Counting helps build awareness of our daily energy consumption. But food is more than calories, and reducing it to a number risks oversimplifying its nourishment. Unhealthy counting as well as being time consuming, calorie counting can lead to restrictive behaviors or unhealthy habits. It may be tempting to eat highly processed foods because calories are clearly displayed on packaging and easier to count, or to exclude nutrient-dense foods like oily fish and nuts purely on the basis of their calorie content. CAN I RELY ON THE SCALE? If you’re trying to lose weight, stepping onto the scale feels like a moment of truth. But the number doesn’t show what’s actually happening in your body. Your weight can fluctuate after just one meal, and over a day. We’re often heavier in the evening after eating and drinking; salt, alcohol, medication, and menstruation can also cause water retention. One study found that weight is highest after the weekend and the ideal weigh-in time is Wednesday morning before consuming anything. If you want to establish a rough base weight, use the same scale, at the same time, without clothes. In addition, overreliance on the scale could contribute to an unhealthy body image and relationship with food, and for some people it can become a crutch. What doesn’t the scale tell me? Be mindful that a weight reading doesn’t reflect how much body fat you are carrying, your overall body composition, or how healthy you are. Even if the number on the scale isn’t falling, you could still be losing body fat, gaining muscle, sleeping better, and improving your gut health. Homeostatic hunger refers to the physical feeling of wanting to eat, caused by the need for energy. Hedonic hunger describes the desire to eat for pleasure. When we smell or eat something tasty, the brain releases pleasure hormones like dopamine. We then associate that food with the feeling of pleasure we experienced, making us want to eat it again, or eat more of it than we need. Psychological and emotional factors affect the balance between hunger hormones in ways we don’t yet fully understand. Tiredness can also have an impact. The human body has a complex system of hormones that interact in myriad ways. For example, cortisol, a stress hormone suppresses appetite, but in cases of chronic stress, it can enhance appetite. It seems as we age, we lose connection with our innate hunger signals. For instance, people easily confuse thirst for hunger. Fighting against feeling hungry can do more harm than good, but it’s good to recognize and acknowledge whether your body is actually in need of fuel or if your hunger is actually for the pleasure you associate with food. If you feel tired and your stomach is growling, it’s likely your body lacks energy and you need to refuel to satiety. If this happens often, eat a little more at mealtimes, consider increasing your carbohydrate intake, or take a snack with you when out and about. If it’s hedonic hunger that you keep feeling, it’s likely you’re in need of satiation. Research suggests some types of food can be more satiating than others. A diet rich in fiber or high in protein suppresses ghrelin (the hunger hormone) effectively.

Part 4: Nutrition

Part 4: Nutrition

Based on the book "The Science of Nutrition" by Rhiannon Lambert

What are the elements of a poor diet? A poor diet is one that isn’t providing enough crucial nutrients to keep you in optimal health, or your body’s energy needs and your appetite in balance. Over the long term, it could also have life-limiting effects. Poor diet is not only about eating too much of the “wrong” foods; it can also mean not consuming enough nutrient-dense foods. Why do so many of us have poor diets? The reasons people don’t eat a healthy, balanced diet are complex and often interlinked. They can range from access to a wide choice of different foods to psychological influences they may not even be aware of. Lack of education about food, and an unhealthy relationship with it, are key factors contributing to poor diets in developed countries. Giving sweets to an upset child arguably creates an emotional association; as an adult, that person is more likely to reach for sugary carbohydrates to self-soothe against stress or anxiety. Animal and human studies show that certain foods, especially those high in fat, carbohydrates, and salt, stimulate the brain’s reward centers. A research review suggests meals eaten socially could be a third to a half bigger. Processed food isn’t automatically inferior or unhealthy compared to fresh. Some nutrient-rich whole foods like vegetables, fish, milk, or whole grains are processed simply for storage or preservation; for example, freezing happens straight after harvest, so freshly picked foods arrive in stores at near peak nutritional value. Highly processed foods should be limited in a healthy, balanced diet. They typically combine already modified ingredients and additives and are either ready to eat or need minimal preparation; examples include many sweets, chips, baked goods, and ready meals. They lack much of the original whole food’s fiber, making them easily digestible, while added salt, sugar, and fats also make them highly palatable. The mechanisms behind their suggested addictive nature include sugar’s ability to stimulate the brain’s reward centers. Checking the nutrition panel on food packaging can, for example, help you spot that a low-fat yogurt has had extra sugar added, making a higher-fat option with less sugar a smarter choice. Rules around nutritional labeling vary in different countries; in the US, most prepackaged foods must show the following per serving: • Energy in kilocalories or calories • Total and saturated fats • Protein • Total carbohydrates from sugars that are added and naturally present • Salt, which may also be listed as “sodium”. No added sugar “Sugar free” means one serving contains less than 0.5g of sugar, both natural and added. “No added sugar” refers only to sugars added during processing, not naturally occurring sugar, such as fructose in fruit. A no-added-sugar fruit smoothie, for example, could potentially contain more sugar than a can of soda. Low/light The claim “low” refers to the following amounts compared to a given reference amount: <40 calories; <3g total fat; <1g saturated fat (with no more than 15% of calories coming from saturated fat); <140mg sodium; and <20mg cholesterol (and only when a food contains <2g of saturated fat per serving). Food that derives less than 50% of its calories from fat can be labeled “light” or “lite” if its total amount of calories is decreased by at least 33.3% or its fat content is reduced by at least 50% compared to a standard/original version. high fiber Food products that contain at least 10% DV or 2.5g of fiber per serving can claim they are a “good source of fiber,” and those containing at least 20% DV of fiber or 5g or more of fiber per serving can label the product with a high fiber claim. Natural/ organic The FDA defines “natural” as having nothing artificial or synthetic (including all color additives) included in or added to the food. The claim “100% organic” can appear on any product that contains 100% organic ingredients (excluding salt and water). Good Source/Excellent Source If a food contains 10–19% DV of a certain nutrient, it’s considered a “good source.” An “excellent source” has at least 20% DV of a certain nutrient. Carbohydrate is the main fuel for any exercise; it promotes strength and endurance, delays muscle fatigue, and speeds up recovery, meaning fewer injuries. It is converted to glucose, and excess is stored as glycogen in the liver and muscles, providing instantly available energy. The longer and/or more intense the training, the faster glycogen depletes and fatigue can set in. Resistance training plus protein builds muscle, but without enough carbohydrate, protein will be used for energy instead. Stepping up training can increase appetite, so it’s easy to eat more than your body really needs. Protein’s primary role is to build, and rebuild, muscle. Aim to eat 0.8g–1g per kg/2lb of body weight daily—in the lower range for endurance and higher for strength training. Opt for lean or low-fat foods like skinless chicken and yogurt. Protein is more effectively absorbed from food than supplements. Signs that your diet isn’t meeting your energy needs include fatigue, poor sleep quality, and irregular bowel movement.

Part 3: Water, Metabolism, and Biotics

Part 3: Water, Metabolism, and Biotics

Based on the book "The Science of Nutrition" by Rhiannon Lambert

It is not easy to find even one system of the body that does not require water. Water enables the circulatory system to carry essential oxygen and nutrients to cells. Our kidneys need water to filter out waste products. It helps us cool off via sweat when we are too hot. It helps the digestive system do its job. And the list goes on! When it comes to the brain, 75 percent of its mass is water, so alongside the bodily processes, hydration also plays a crucial role in regulating mood, productivity, and concentration. Drink 2.7–3.7 liters of water every day. A typical mug or glass has a capacity of 7oz (200ml), so you’d need to have 11.5–15.5 drinks a day. Bear in mind that these are the recommended daily intake amounts and some people may need more. Aim for 15.5 cups (3.7 liters) daily if you easily get to 11.5 cups (2.7 liters). Signs of dehydration include dry mouth, dark yellow urine, feeling tired, thirsty, and dizzy, and urinating fewer than four times per day. Studies show that at about 1 percent dehydration (equivalent to 1 percent of body weight water loss) there are negative effects on mental and physical function, which become more severe as dehydration increases. What is metabolism? Metabolism is the term used to collectively refer to every single chemical reaction that takes place in your body in order to keep it alive. Metabolism is closely linked to nutrition, because the food we eat provides the energy required to fuel metabolism. On average, we use 10 percent of energy intake on digestion itself, 20 percent on physical activity, and a whopping 70 percent by organs and tissues to keep the body alive. Every process in the body, from breathing to thinking, uses energy. A person’s basal metabolic rate (BMR) is the number of calories needed to sustain their life while they are sitting still. How the body metabolizes the energy it consumes is played out in a balancing act between two states—fed and fasted. During or after eating a meal, food is broken down and glucose is released into the blood for cells to absorb and use as fuel. When the body has obtained more glucose from food than is needed by cells, they stop absorbing it. The resulting increase in blood glucose levels triggers the release of insulin. Insulin stimulates liver and muscle cells to reverse the conversion of glycogen into glucose that takes place during the fasted state and, instead, absorb the surplus glucose in the bloodstream, convert it to glycogen granules, and store it for future use. Insulin also triggers the conversion of glucose to triglycerides (fats) in adipose tissue. Surplus fatty acids from the diet are also stored in adipose tissue. Several hours after eating, blood glucose levels drop, which triggers the pancreas to release glucagon. This stimulates the liver and adipose tissue to metabolize glycogen stores, which releases glucose into the bloodstream to make it available for the body to use as energy. After prolonged fasting, fat stores in adipose tissue are broken down into glycerol and fatty acids in the liver. Ketone bodies are a by-product of this reaction. Protein is used for fuel only as a last resort. WHAT ARE CALORIES? This unit of measurement is used to estimate how much energy there is stored in the chemical bonds of the foods we eat. Your body may not gain the full amount of energy that is released from foods. Foods full of fiber, like nuts, for instance, take more energy to digest and two people may absorb different levels of nutrients from the same quantity of the same foods. Gut health and the length of the intestines play a role in how much energy your body is able to absorb from foods. It’s important to remember that calories are not everything! A number definitely does not dictate how healthy you are or the quality of nutrition you consume. You could be in your body’s ideal calorie-intake range by eating a chocolate brownie for breakfast, lunch, and dinner, but this won’t provide you with all the key macronutrients, micronutrients, and fiber you need to be healthy and happy. Portions of Fruit and vegetables: 1 portion = 1 handful/3oz/3–4 heaped teaspoons cooked spinach/green beans = 1 medium tomato = 1 medium apple/orange/banana = 5oz of fruit juice (maximum per day). Portions of starchy carbohydrates 1 portion = 2 handfuls dried rice/pasta/couscous (less for 4 portions) = 1 fistsized baked potato = 2 slices bread. 2-3 portions of Protein 1 portion = half a handful salmon/chicken/steak = 4oz cooked beans/lentils = 1oz/palmsize nuts or seeds. 2-3 Portions of Dairy and alternatives 1 portion = 1oz/2 thumbs cheese = 7oz low-fat cow’s milk or unsweetened dairy alternative (4oz on cereal) = 4oz low-fat yogurt. The dried seeds of legumes are called pulses. They include lentils, chickpeas, black or pinto beans, soybeans, and kidney beans. These robust seeds contain varying amounts of the essential amino acids that make up protein. A 3.5oz (100g) serving of red lentils, chickpeas, or kidney beans provides 7.5g–8.5g of protein, which makes up a nice chunk of your daily requirement. You can save much money by getting more of your protein from beans rather than meat, adding lots of valuable fiber to your diet at the same time. Probiotics are live strains of bacteria consumed to directly increase the population of “good” bacteria in the gut. Prebiotic foods feed existing gut bacteria so they can thrive and work effectively. What are the benefits? Research suggests probiotics are mainly of benefit when your gut microbiome is out of balance, for instance, to relieve diarrhea caused by infection or after a course of antibiotics. Although studies are limited, certain types of bacterial strains have been found to reduce symptoms of irritable bowel syndrome, particularly bloating. Otherwise, a study found that eating fermented foods 1–5 times weekly is associated with a subtle change in gut bacteria. In general, though, healthy people should not require probiotic supplements. A key benefit of prebiotic foods is that different types of the non digestible fibers within the food are broken down by gut bacteria, which then produces gut protective short-chain fatty acids. Some studies show that eating a type of dietary fiber called inulin can help maintain the gut’s mucus barrier and prevent inflammation. It’s best to increase prebiotic food intake gradually, to avoid bloating.