Muscle, fat, weight...

Originally Posted by BiochemGuy

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Because I wrote only about effects of weight on metabolism, not all factors of metabolsim. I wrote about the effects of TEF(thermic effect of food) on page 4 of the "protein powder for weightloss" thread. The size of a meal has no effect on metabolism, only total calorie intake for the day and where those calories come from.

Protein has a TEF of 30% meaning 30% of the protein calories you consume are burned during digestion and processing of those protein calories.

Carbohydrates have a TEF of 6%
Fat has a TEF of 3%

So If you eat 3000 calories a day of equal amounts of calories coming from protein, carbs, and fats your TEF would be.

1000 calories of Protien minus 30% for TEF equals 700 calories.
1000 calories of Carbohydrates minus 6% for TEF equals 940 calories.
1000 calories of fat minus 3% for TEF equals 970 calories.

So the total calories left after TEF would be 2610 calories and 390 calories burned for TEF.

It wouldn't matter if you ate these 3000 calories in one meal or ten meals. the thermic effect would be the same.
The whole thing about larger or smaller meals effecting TEF differently is nothing more than a myth with no science to back it up. The thermic effect of food is in response to calories and not meal size.





You are right about cholecystokinin making you feel full.
The reason fat has been looked at as being bad is mainly due to the fact that is has about twice as many calories per gram. The old way of thinking was that to lose weight you have to consume less calories than you burn, and since fat has the most calories per gram cuting out fat intake would be the best way of reducing calorie intake.

Most didn't take into consideration that fat is also very filling per gram since its digested slowly and the release of cholecystokinin from fats will also help to keep you feeling full.

They also used to think fat was unhealty and raised cholesterol and therefore should takin out of the diet before carbohydrates.

We now know that not all fats are equal. The polunsaturated fats reduce cholesterol, monounsaturated fats don't effect cholesterol and its the saturated fats that increase cholesterol.

Usually foods high in fat are also high in cholesterol and it was thought that if you eleminated eating fatty food then you would get less cholesterol as well. Cholesterol from food actually has little effect on raising blood cholesterol. They thought for many years that eating cholesterol raised blood cholesterol but this isn't always the case. Your liver makes about 2000mg of cholesterol per day. The more cholesterol you eat the less cholesterol your liver makes.

So take a person who eats no cholesterol at all. their liver will still make 2000mg of cholesterol. If they eat 2000mg of cholesterol their livers will make zero cholesterol. either way they end up with the same blood cholesterol levels. Only if a person ate more cholesterol than their liver made would food cholesterol effect blood cholesterol. this isn't usually the case in most peoples diets.

Carbohydrates also raise cholesterol since insulin from carbs stimulates the liver to produce more cholesterol. This is why people on low carb Atkins type diets usually have their blood cholesterol decrease or stay the same even though they are eating alot of saturated fat and food cholesterol.

It also explains why when doctors put people on low fat high carb diets to reduce cholesterol, it usually dosn't work. This is what most doctors did for years and many doctors still do.

So fat was looked at as being bad cause it has more calories per gram, raises cholesterol, and usually found in high cholesterol foods. Which I just explain why this isn't the case. Fat was looked at as being evil for so long that it's going to take awhile for people to come around, especially doctors who have been preaching for years that fat is bad for you.