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.

Part 2: Fiber, Starch, and Vitamins

Part 2: Fiber, Starch, and Vitamins

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

Soluble fiber is found in the flesh and pulp of many fruits and veggies, grains, seeds, and legumes. This type of fiber dissolves in water to form a gel-like substance that helps make stools soft. This enables them to progress through the gut with ease, preventing constipation. Soluble fiber (in oats, for instance) slows down digestion, which helps with satiety and also with regulating blood sugar levels. Soluble fiber has another great benefit; in the small intestine, its presence reduces the absorption of cholesterol into the bloodstream, which has the positive effect of reducing the levels of LDL cholesterol (the bad type of cholesterol; cholesterol) circulating in the blood. Insoluble fiber is found in the skins and seeds of many fruits and veggies, nuts, seeds, whole grains, rice, and wheat bran. As the name suggests, insoluble fiber does not dissolve in water, so it can be only partially broken down by digestion. It helps to push things along in your digestive tract, preventing digestive problems. Consuming enough insoluble fiber promotes regularity of bowel movements and helps regulate blood sugar levels. Carbohydrates made up of high proportions of beta-glucose monomers, such as cellulose, are referred to as resistant starches because they cannot be broken down by the small intestine. They pass into the large intestine, where they are fermented by gut bacteria. This fermentation process produces short-chain fatty acids (SCFAs), which stimulate the immune system and can impact mental health. Cooked and cooled potatoes and rice contain resistant starch, which is also found in whole grains like barley, oats, and sorghum, green bananas, and beans and legumes. Our bodies cannot make all the micronutrients we need to function, so this requirement is met solely by diet. Most people enjoying a healthy, balanced diet will easily obtain enough vitamins. Vitamins come in two main forms, water-soluble and fat-soluble. Water-soluble vitamins are easily lost through bodily fluids (and in cooking) and must be replaced each day. • B vitamins play an important role in keeping the nervous system healthy and helping our bodies release energy from the foods we eat. Folate (vitamin B9) helps with brain and spinal cord development in unborn babies. Sources of B vitamins are: • B1 Peas, bananas, nuts, whole grains • B2 Milk, eggs, fortified cereals, mushrooms • B3 Meat, fish, wheat flour, eggs • B5 Chicken, beef, eggs, avocado • B6 Pork, soybeans, peanuts, oats, bananas, milk • B7 is needed in trace quantities, and is available from many food sources, so will be present in a varied and balanced diet, B9 Leafy greens, chickpeas, edamame beans, broccoli, liver, foods fortified with folate • B12 is found only in animal products, such as eggs, meat, or fish, or in fortified plant foods, such as some nutritional yeast products. • Vitamin C is often hailed as the cure to colds and flu because it contributes to healing. It also maintains healthy skin, blood vessels, and cartilage, and plays a role in the production of collagen, which maintains our skin’s elasticity and strength. Sources include oranges, peppers, broccoli, and bananas. Fat-soluble vitamins tend to accumulate within the body so are not needed in the diet on a daily basis. Vitamins A and E are powerful antioxidants, helping to protect cells from free radicals and aging. Vitamin A contributes to cell renewal and repair, but note that excesses during pregnancy may harm the baby. Vitamin E reduces the effects of skin aging and the risk of skin cancer. Sources of vitamin A include carrots and sweet potatoes. Sources of vitamin E include almonds and avocados. • Vitamin D is unique because it is a hormone that we can produce in our own bodies with exposure to sunlight. This means we don’t need to get it from diet if there is enough exposure. However, with the use of sunscreen and the lack of sunlight in parts of the US and during winter, we are advised to supplement with vitamin D if our blood levels are low. Dietary sources include egg yolks, oily fish, and fortified foods. • Vitamin K is important for wound healing (we need it for blood clotting), and some evidence links it to bone health. Sources include green leafy vegetables, some cereal grains, and vegetable oil. Unlike vitamins, which are organic compounds (made by plants or animals), minerals are inorganic chemical elements that come from soil, rock, or water. They are absorbed from the environment by plants as they grow, and by animals that eat those plants. There are many minerals, each with benefits. Try to include each type in your diet regularly. You need some minerals in greater quantities, such as calcium, chloride, magnesium, phosphorus, potassium, sodium. Others, like iodine, iron, selenium, and zinc are needed in trace quantities. • Calcium is a vital component of bone and teeth, and a key nutrient for the nervous system, muscles, and heart. Sources include milk, yogurt, spinach. • Iodine deficiency affects nearly one-third of the world’s population. This mineral is essential for normal thyroid function and the production of thyroid hormones, which are involved in many processes in the body such as growth, brain development, and bone maintenance. Thyroid hormones also regulate the metabolic rate. Sources include fish, dairy products, eggs, seaweed. • Iron deficiency is the most common nutritional deficiency in the world and the only one that is prevalent in developed countries. More than 30 percent of the world’s population has anemia. Lack of iron lowers the ability of the blood to carry oxygen. Iron has many benefits, including improved immune and brain function. Sources include shellfish, broccoli, red meat, tofu. • Magnesium plays a role in more than 600 cellular processes, including energy production, nervous system function, and muscle contraction. Sources include avocados, nuts, leafy greens. • Manganese helps make and activate some of the enzymes in the body that carry out chemical reactions such as breaking down food. Sources include bread, nuts, breakfast cereals, and green vegetables. • Potassium is important for blood pressure control, fluid balance, and muscles and nerve function. Sources include bananas, spinach, potatoes, apricots. Phosphorus helps the body build strong bones and also release energy from food. Sources include red meat, dairy, fish, poultry, oats, bread. • Selenium helps the immune system work correctly, prevents damage to cells and tissues, and promotes the health of the reproductive system. Sources include Brazil nuts, eggs, meat, fish. • Zinc supports the immune system, hormone production, and fertility. It can help reduce skin inflammation and support wound healing and protects against UV damage from the sun. Sources include shellfish, red meat, eggs, chickpeas.

Part 1: Carbs, Protein, and Fat

Part 1: Carbs, Protein, and Fat

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

Did you know you can get most of your vitamins and minerals from plants. Plant foods come in various colors and shades, and their color is linked to the nutrients they contain. For instance, orange often indicates the presence of vitamin A; purples indicate antioxidants; greens contain vitamin K and iron; and red vegetables contain lots of vitamin C. So a colorful diet will give you a well-varied nutrient intake. Let’s take a look at our 3 macronutrients starting with carbohydrates! What are carbohydrates? Carbohydrates are the body’s greatest energy source. They provide the body with glucose to use for energy, which can also be stored (as glycogen) for future use. Carbs also play a valuable role in gut health, by providing useful fiber to the digestive tract. Glucose is the preferred energy source for muscles during strenuous exercise. It is only when the body’s glucose supply is depleted that it turns to fat for energy. The body also requires glucose to fuel multiple unconscious biological processes. Glucose is essential fuel for the brain, aiding in concentration. Carbohydrates play an important role in generating the brain’s serotonin supply. This mood-regulating hormone is made with tryptophan, an amino acid obtained through protein in the diet. Carbs help convert tryptophan into serotonin, so eating carbs may help enhance mood. This might explain why carbs and sweet foods are often treated as comfort foods. In the small intestine, the less starchy complex carbs are broken down into simple carbs. All non-glucose monosaccharides are converted into glucose in the liver, which is released into the bloodstream. It is either used immediately or converted into glycogen (a polysaccharide of glucose), which is stored in the liver and muscles for later use. Fiber refers to any complex carbohydrates that cannot be broken down by the digestive enzymes in the small intestine. This fibrous matter moves into the large intestine, where it helps produce highly useful short-chain fatty acids and nourishes the lining of the gut. Single molecule Monosaccharides "Mono" means "one"; "saccharide" means "sugar." These are carbs in their most basic form. Glucose: grains, pasta, Fructose: fruit, honey, and Galactose: dairy. Two molecules Disaccharides: When two monosaccharides bond chemically, they form a disaccharide. Lactose: dairy, Sucrose: sugar beet, cane sugar, and Maltose: molasses, beer. Multiple molecules Polysaccharide: Carbs can be made up of hundreds, even thousands, of monosaccharides. These are called complex carbs which include many vegetables, beans, lentils, and whole grains. There is no such thing as an inherently good or bad carb. All foods have a place—it’s about finding the right balance for your own body. There’s a strong case for reducing refined carbs, like white bread, and opting for complex carbs, like whole grains, which release energy slowly. While refined carbs are great for providing energy quickly, they usually lack essential nutrients. What is protein? The macronutrient protein is a major player in the diet. It is the body’s building block, used to form and repair muscles, skin, hair, and nails, for instance. Protein also enables many of the body’s vital metabolic functions. Proteins are made up of amino acids. The body can produce many of the amino acids it needs to make peptides and proteins, but nine of them, known as essential amino acids, must be sourced from the diet. Because the body doesn’t store proteins in the same way it does other macronutrients, it needs to consume proteins every day. Food sources containing all nine essential amino acids in sufficient quantities are known as complete proteins. They are found in animal products and a few plant sources. Incomplete proteins are plant-based sources of protein that don’t contain all nine essential amino acids, or don’t have sufficient quantities of them to meet the body’s daily requirements. Although “incomplete,” they are no less valuable than complete proteins as protein needs are met across the whole day, not just at each individual meal. Vegans and vegetarians are advised to eat a wide variety of protein-rich and fortified foods to ensure they consume all nine of the essential amino acids each day from both complete and incomplete sources. In the US, adults are advised to consume 0.8g protein per kg (2lb) of bodyweight per day. (Particularly active people should increase this intake to 1g.) Based on average weights and activity levels, daily intake should be 56g for men and 46g for women. That’s about two palm-size portions of meat, fish, tofu, nuts, or beans. As we grow older, our bodies become less efficient at using protein. Increasing protein intake makes it more likely we’ll meet daily requirements. What is fat? Fat is a macronutrient found in many food sources. Consuming fats is vital to the body’s function, including processes such as brain activity, hormone production, and the body’s absorption of other nutrients from the diet. Monounsaturated fatty acids (MUFAs) are typically liquid at room temperature and are fairly stable for cooking purposes. The most common MUFA is oleic acid, which is present in olive oil in high amounts. Excellent sources of this healthy fat are avocados, nuts, seeds, canola oil, fish oils, and nut oils. Polyunsaturated fatty acids (PUFAs) are found in sunflower seeds, oily fish, walnuts, flaxseeds, and vegetable oils, including safflower, sunflower, and corn oils. Omega-3 and omega-6 are polyunsaturated fats. Omega-3 plays a crucial role in the production of hormones, in the immune system, blood clotting, and cellular growth. Studies show that consuming omega-3 fats is linked to reduced incidence of health conditions, including neurodegenerative disease, heart disease, and diabetes. High-density lipoproteins (HDL) are good cholesterol. These particles contain a high proportion of protein to cholesterol. They protect the body by carrying LDL cholesterol away from arteries to the liver, and they have anti-inflammatory properties. Low-density lipoproteins (LDL) are bad cholesterol. They have a lower proportion of protein to cholesterol. These types of fatty acids carry cholesterol to the cells. Too much LDL can be harmful because it sticks to the inside walls of your arteries, causing buildup of fatty material, limiting blood flow and leading to heart conditions and stroke. We want to aim for a preferential ratio between HDL and LDL cholesterol. There are measures we can take to increase our HDL cholesterol levels and lower LDL. Non Dietary actions include exercising regularly and stopping smoking. Avoid trans fats completely, and include the following foods regularly in your diet. Purple fruits and vegetables are rich in anthocyanins, which may help increase HDL cholesterol levels. Oily fish 1–2 times a week may help increase HDL cholesterol levels and benefit heart health. Olive oil increases HDL levels in healthy people, the elderly, and those with high LDL cholesterol. Whole grains are linked to a lower risk of heart disease. Oats and barley contain beta-glucan, which lowers LDL cholesterol. Nuts are rich in cholesterol-lowering fats and fiber, as well as minerals that are linked to improved heart health. Avocados contain monounsaturated fatty acids and fiber, both of which lower LDL cholesterol. Legumes such as beans, peas, and lentils help lower LDL levels and are a good source of plant-based proteins.