Diet are the foods consumed by a person. Dietary habits are habitual decisions an individual makes when choosing foods, and can define a culture and religion. Proper nutrition requires ingestion and absorption of vitamins, dietary minerals, and food energy (in the form of carbohydrates, proteins and fats). Diet determines quality of life, health and longevity.

• Caloric requirements:
  • <6mo, 110-120 cal/kg/day
  • 1yo, 90-100 cal/kg/day
  • 15yo, 44 cal/kg/day
  • In adults, 2,700 cal (or 11,300 kJ) for men, and 2,100 cal (or 8,800 kJ) for women
• Eat roughly the same amount of calories that your body is using
• Increase consumption of plant foods (particularly fruits, vegetables, legumes, whole grains, nuts)
• Limit intake of fats (prefer less unhealthy unsaturated fats, cf. saturated and trans fats)
• Limit intake of sugar
  • Replace with sweeteners, including:
    • Saccharin (400x sweeter than sugar and contains no calories; the original sweetener discovered in the late 1800's, which was listed as a potential human carcinogen (bladder cancer) in the 1970's based on lab tests in rats, but after 30 human trials showed it was not reproducible, has had its warning label removed)
    • Aspartame (200x sweeter than sugar, found in Diet Coke, and contains no calories; it has more than 100 studies supporting it's safety, although some Pt's report side effects of headache, diziness, affecting mood, and must be avoided in Pt's with PKU because it contains phenylalanine)
    • Sucralose (600x sweeter than sugar, with 100 studies demonstrating its safety as an all purpose sweetener, including for baking as it is heat stable)
    • Acesulfame potassium (200x sweeter than sugar and contains no calories, found in Coke Zero, with more than 90 studies supporting its safety)
    • Stevia (made from a South American plant, has no calories, and been around for centuries, although some find it has a metallic aftertaste; they are generally recognized as safe). Some Pt's may find that aspartame tastes better and more thicker than saccharin
  • Even with sugar substitutes however, beware of tooth staining nonetheless. Teeth enamel, although the hardest substance in the body, contains microscopic pits and ridges that can hold particles of food and drink, including being embedded by pigments from dark-colored drinks such as coffee (chromogen, some tannins), tea (tannins, with black tea worse, when compared to herbal, green and white teas, but still stains teeth), soda, wine (chromogens, tannins), cola (acidity), sports drink (acidity), berries (blueberries, blackberries, cranberries, cherries, grapes, pomegranates, juices; and other foods/beverages made from them), sauces (soy, tomato, curry), sweets (candies, chewing gum, popsicles), smoking. Minimize staining by using a straw, swallowing promptly (cf retaining things in the mouth for long periods of time), and swishing with water (but don't brush within 30 minutes after consumption of an acidic food or beverage, since enamel is highly vulnerable to abrasion in this time)
• Limit salt/sodium consumption, and ensure salt is iodized (i.e. prevents iodine deficiency, which can lead to ID and developmental disabilities)

Dieting is the practice of eating food in a regulated fashion to decrease, maintain or increase body weight. It is often used in combination with physical exercise to lose weight, but can also be used to gain weight (usually muscle). Research shows that weight loss can not be achieved by physical activity alone, and must include dieting, because increased activity increases appetite. Diets include:

• Low calorie
• Very low calorie (VLCD) are diets with food energy of <800 calories (3,300 kJ) per day. They are usually formulated, nutritionally complete, liquid meals to be mixed with water, that contain the recommended vitamins, minerals, trace elements, fatty acids and protein. Carbohydrate may be entirely absent. It is prescribed for rapid weight loss (1.5-2.5kg/week) in Pt's with a BMI>30, or if BMI>27 and being overweight has serious health risks
  • Even most reasonable thinspiration authors will recommend around 1,200 calorie intake, and not to drop below 1,000 calories a day, because it will cause extreme cravings and result in a binge when an unlimited supply of food is offered (e.g. at a party, buffet, home alone, passing by the kitchen)

RCT's show that there are no differences between the diets above, with all losing 2-4kg, so long as calories are reduced, regardless of macronutrients emphasized. Methods however, which can be used to lower caloric intake include:

• Low carbohydrate, with TEF (thermic effect of food) illustrating costs of processing food for use and storage, and is 27.5% in protein, as compared with 10% for both fats and carbohydrates. Proteins are usually thought to be most filling, followed by fats (diets of which are known as ketogenic diets), and then carbohydrates, which suggests that high protein-low carb diets may elicit the best compliance
  • It is also hypothesized that there are negative caloric foods, which require more energy to digest than recovered from the food, including raw celery and grapefruit
  • Carb cycling is a variation, involving low-carb with intermittent periods of high (or moderate) carbohydrate consumption. It helps to maximize fat loss, whilst maintaining the ability to perform HIIT. During refeeding, up to 1kg weight gain is normal, which consists mainly of water, and can be lost within 4 days. The purpose of the refeed is to refill depleted glycogen stores, upregulate hormones and thyroid activity suppressed during dieting, and provide a psychological break to make the diet easier to bear. Refeeding howver, can lead to fat gain, if more carbs are consuemd than required to replenish glycogen stores. Where a normal ketogenic diet involves <50g carb per day, the typical refeed consists of up to 600g carbs. As apart of a reverse 5:2 diet, carbs can be cycled twice a week, or less often, depending on desire
• Low fat, recommended also because of their positive cardiovascular effect
• Low GI (glycemic index)

Reverse dieting involves a controlled, gradual increase in daily calories (cf dramatically reverting caloric intake back to normal), with the purpose of increasing metabolism (usually as measured by basal HR, but can also be measured using body temperature), after downregulation due to caloric restriction (causing weight loss). Increments should be around 100 calories at approximately weekly intervals, until you've reached your average TDEE (or start gaining weight, where you can continue or pull back).

• There is no evidence that microwaving foods will cause the food to become carcinogenic. It is important however, to ensure that plastics are not used unless they expressly indicate they are microwaveable

• Gram calorie (cal), is the energy required to raise temperature of 1g of water by 1 degrees C at 1 atm. 1 calorie=4.2 J. It is widely used to describe food energy. To lose 1kg, there needs to be a calorie deficit of 7,700 cal, which over 1 week would require a deficit of 1,100 calories per day
• Dress size, where the dropping of 1 dress size can be achieved by loss of between 5-8kg

• Only Kosher foods are permitted by Judaism
• Only Halal foods are permitted by Islam
• Buddhists are generally vegetarians, but depends on the sect
• In Hinduism, vegetarianism is ideal
• Issues surrounding morality, personal impact on the environment
• Incorrect public assumptions regarding dieting

• Dieting usually does not lead to sustained weight loss for the majority of people
• Weight loss by dieting may increase mortality rate for individuals who are otherwise healthy

Paperwork for "Nutrition notes" includes:

• Affix Pt label
• Thank you for filling out these Nutrition Notes as accurately as possible. Of the food and drinks sent to this Pt, please specify the percentage eaten (for example, 0, 25, 50, 75, or 100% for each item). Wherever possible specify type of food/drink eaten
• Table, where every column is a repeat of the next column, but for another date. The top row includes Date: __/__/___. For each cell, the % eaten is to be inserted, as indicated by the top row. The rows are divided into:
  • Breakfast, including Cereal with Milk, Toast, Drink (___), Other (___)
  • Morning tea (specify)
  • Lunch, including Meat (___), potato/rice, salad, sandwich, dessert (___), drink (___), other (___)
  • Afternoon tea (specify)
  • Dinner, including soup (___), meat (___), potato/rice, salad, dessert (___), drink (___), other (___)
  • Supper (specify)
  • Dietitians analysis, including Calories, Protein

• Physical activity
• Eating disorders (anorexia, bulimia)
• Self care