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.
