4. Hunger
“If you get too few calories, the body stops burning fat…”
THE TRUTH: Metabolism does slow down when you restrict calories, but the effect is greatly exaggerated. When you eat less than you burn, your weight starts to fall; lower body weight leads to lower energy expenditure. This is the first sign of metabolic adaptation, and you can expect metabolism to slow by roughly 30 calories for every kilo lost. In addition, metabolism slows in response to reduced calorie intake, by around 5-10 %, because the body produces, among other things, less thyroid hormone. The only way to fix your metabolism is either to return to your starting weight or to start eating according to your energy needs.
It is worth noting, though, that in extreme cases, such as bodybuilders who drop their body fat percentage very low, for example during competition (body fat percentage 4-5), metabolic adaptation is noticeable and can even exceed 20 %. The body controls metabolism through a feedback system made up of the hormone leptin (which is produced in fat cells) and other hormones. When the amount of fat in the body is low, this has a noticeable effect on metabolism. The reverse also holds: the more fat you have, the less your metabolism is affected by cutting calories.
CONCLUSION: In practice, hunger has only a marginal effect on metabolism, independent of weight loss. Only a very small share of trainees ever reach a body fat percentage so low that hunger would have a noticeable effect on metabolic rate.
5. Food combining
“Don’t eat carbohydrates and fat together, because it leads to fat storage…”
THE TRUTH: This superficial theory rests on the claim that carbohydrates cause a rise in insulin, which in turn causes the fat from the food you just ate to be stored. It is yet another example of what happens when nutrition gurus and their flimsy theories about how the body’s metabolism works are taken seriously, without having any real basis.
The body digests different nutrients at different speeds. Fatty acids from food enter the bloodstream more slowly than carbohydrates, and by the time carbohydrates are being absorbed, fatty acids from the previous meal are still in the bloodstream. Digesting a whole meal can take 5-6 hours. It is also worth knowing that a) protein triggers insulin release in the same way as carbohydrates, and b) fat is in fact stored perfectly well without any help from insulin, with the aid of ASP protein.
CONCLUSION: Consuming fat and carbohydrates separately in the belief that less fat will then be stored is unfounded. What determines how calories are used is the total calorie intake over the day, not manipulating the amounts of fat and carbohydrates at individual meals.
6. Fruit and fructose
“Fructose is more easily stored as fat, so be careful with eating fruit…”
THE TRUTH: To avoid misunderstandings, a short primer on how this type of sugar behaves in the body is in order. Fructose is a monosaccharide, a type of sugar that does not cause a large rise in blood sugar and is stored as liver glycogen, unlike glucose, which can be stored as muscle glycogen. The liver stores about 60-70 grams of glycogen; any further fructose is converted into fatty acids. A large amount of fructose does no good, but an irrational fear of fruit is not right either. The fact is that diets that include fruit have a good effect on cholesterol levels compared with, for example, diets with less fruit. Fruit does not contain much fructose, and to fill your liver glycogen stores you would have to eat 6-7 large apples in a row.
A large amount of fruit is therefore not a fructose problem; the real problem is heavily processed foods such as soft drinks, ice cream and other sweets. Because of its sweetness and low cost, the preferred sweetener in the food industry is HFCS (high fructose corn syrup). HFCS consists of 90 % pure fructose, so it is artificial and harmful to health when used in large amounts. Fortunately, the use of HFCS is mainly widespread in the US food industry…
Some mass gainers contain fructose, so it is worth reading the product information on the packaging. After training, the goal is to replenish muscle glycogen stores and, as mentioned, fructose cannot be stored as muscle glycogen.
CONCLUSION: Fruit is rich in vitamins and fills you up well, which goes hand in hand with its low energy content, so you can eat fruit with a clear conscience whenever you like. If you want to avoid the negative effects of fructose, steer clear of heavily processed products, especially soft drinks.
Translated from Body magazine; Author: Martin Berkhan
Author: Greta
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