Summary of key points from Gary Taubes
The "calories in, calories out theories" are wrong as a means for dieting. They are true only when the body is fully in balance and can keep the delicate relationship. Because
1. It only takes very few over a period to overeat, calorie wise (20 cals per day, which is almost unmeasurable with normal eating);
2 Many populations who are starving are also overweight (quotes extensive research)
3 If you reduce cals over a period, your body gets good at retrieval, you also get less active, your metabolism slows down and binges are highly likely as cravings for carbohydrate increase.
4. To continue to lose weight therefore using this theory you have to cut calories even further and potentially you could still be overweight on a starvation diet. First chance the body has to build up again it does and you quickly return to where you started. This is why low cal diets fail (85%).
The activity of insulin is crucial:
When insulin in the bloodstream rises, fatty deposits are formed; when insulin falls, fat in the cells begins to be used as fuel by the body
Insulin in the bloodstream is raised by carbohydrates including sugar but also starches.
To lower insulin activity we must reduce starch and sugar intake.
Carbohydrate drives insulin which drives fat. To counter the effects of this, cutting carbs will be effective only if protein and fat are increased, otherwise to get glycogen for energy the muscles are robbed, leading to lethargy and unwellness.
The body burns carbohydrates before it burns fat. If you eat plenty of carbohydrates, your body takes longer to get to the fat and needs to burn less of it, because the insulin uses first what is available as blood sugar before allowing your body to turn to the fat cells.
When we eat a meal, insulin is released immediately in several waves to act on the carbs. When insulin is in the bloodstream the fat cells are effectively locked and the fatty acids can't be drawn out to use for energy as the insulin is busy turning the carbs into energy and fat. When the carbs are mostly dealt with, if there is still insulin in the blood, the cells still can't be used for the energy they should provide, so we get that low blood sugar slump and feel tired and hungry. Our cells are wanting more and say so loudly! This is why carbs on a diet can give problems. Stepping up the protein and fat intake gives energy for muscles and doesn't flood the blood with too much insulin. Insulin is still secreted when we eat protein rich foods but in a more measured way. Insulin ensures that proteins are sent to the muscles. No meal should consist of only carbs, even good ones. So cereal, toast for breakfast without protein is not good, but add an egg or some cheese and ham or smoked salmon and you improve it.
People are more likely to be sedentary because they are fat than fat because they're sedentary. If your muscles are being robbed of glycogen on a low cal diet, you don't feel like exercise either.
Pre-diabetics have raised blood sugar because their bodies are becoming resistant to insulin, so it is less effective at taking the sugars from the blood and putting them into fat stores. This results in more insulin production, higher carbohydrate craving and more storage of sugars as fats. Insulin resistance also affects many people as they get older, promoting more fat storage and carb reliance.
Lipoprotein Lipase. LPL . Attaches itself to cells and draws in the fats from the bloodstream. If attached to muscle cell LPL draws fat into the muscle to burn as energy, if attached to fat cells it draws fat into them to store. Oestrogen inhibits LPL in fat cells. If ovaries are removed, LPL increases and attaches much more to fat cells, so more fat is stored in the body. These fatty cells will remain even under conditions of semi starvation. So women may get fatter with menopause.
Exercise, while good for you in many ways, does not really help you lose weight unless you are using it excessively. During activity, the LPL on your fat cells stops pulling in fatty acid energy and your muscle LPL starts to pull in fats to use. If more is needed then it will be taken from your fat stores. But when the exercise stops, this reverses and LPL starts to pull in fat again into fat cells from the available carbohydrates in your blood. This is why you crave carbs after exercise, but should quickly have protein.
HSL, hormone sensitive lipase. This breaks down the triglycerides in your fat cells so the small molecule fatty acids can go through the cell wall
Insulin again
Insulin and the hormones it influences decide how much will be used, how much stored and where. This varies with heredity from person to person, and also according to circumstances, ages, stages and environmental factors. Also how sensitive to insulin your body is, as this decreases with age anyway. If your body has also been experiencing flooding with insulin because of high carb intake, not only will you be storing fat but you will be pre diabetic as your cells will be desensitising themselves to insulin. Muscle cells are more likely to do this than fat cells, so more of the sugars and fats will be going into fat storage cells than muscle cells.
Fructose and alcohol are slightly different in that they are processed directly in the liver, converted into fats and stored in the cells there. Most sugar has glucose and fructose together, so while one is coking up in your liver the other is raising your adrenalin levels. The more of these we have in our diet the more adept the body gets at converting them to fat. Also, there seems to be a link between higher fructose induced fat in the liver with higher insulin resistance in the muscles, which makes it harder to use the muscles effectively. Alcohol forms citrates in the liver that increases the conversion of fructose to fat.
