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Thread: Net Calories and TEF (thermic effect of food) page

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    Net Calories and TEF (thermic effect of food)

    Consider these 2 diets:

    Diet A: 227 g carbs, 70 g fat, 119 g protein

    Diet B: 279 g carbs, 100 g fat, 0 g protein


    Both diets are about 2000 calories. I know that protein has the highest TEF amongst all the macronutrients. So would Diet A actually be slightly less than 2000 calories? In other words, on average, the TEF is 10% of your daily calorie intake. So the TEF of diet B would be (0.10)(2000 kcal) = 200 kcal, and the TEF of diet A would be say (0.15)(2000 kcal) = 300 kcal (for argument sake)?

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    Diet A has more than 2000 calories. The thermic effect of food does not decrease the amount of energy in food; it represents an increase in your metabolic rate. You can subtract that from the energy content of the food if you want, but to be thorough you would need to account for all other effects on your metabolic rate. For example, the thermic effect of carbohydrates is dependent on the type (glucose vs fructose) and on your own insulin sensitivity. Carbohydrates tend to raise thyroid function while unsaturated fats inhibit thyroid function, so you would need to account for that, too. But free fatty acids promote uncoupling. Insulin inhibits the release of free fatty acids. Glucose promotes insulin secretion. Saturated fatty acids do to a much smaller extent.

    Predicting the net effect of a meal on your total energy balance is extremely complicated and no one really knows how to do it completely.

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    Quote Originally Posted by Elliot View Post
    Diet A has more than 2000 calories. The thermic effect of food does not decrease the amount of energy in food; it represents an increase in your metabolic rate. You can subtract that from the energy content of the food if you want, but to be thorough you would need to account for all other effects on your metabolic rate. For example, the thermic effect of carbohydrates is dependent on the type (glucose vs fructose) and on your own insulin sensitivity. Carbohydrates tend to raise thyroid function while unsaturated fats inhibit thyroid function, so you would need to account for that, too. But free fatty acids promote uncoupling. Insulin inhibits the release of free fatty acids. Glucose promotes insulin secretion. Saturated fatty acids do to a much smaller extent.

    Predicting the net effect of a meal on your total energy balance is extremely complicated and no one really knows how to do it completely.
    So would fruits like apples increase TEF? What about fiber? And both diets are approximately 2014 calories.

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    The thermic effect of glucose is higher if you are insulin sensitive but the thermic effect of fructose is always higher than that of glucose, so sugary fruits would probably promote a higher thermic effect than starches.

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    Quote Originally Posted by Elliot View Post
    The thermic effect of glucose is higher if you are insulin sensitive but the thermic effect of fructose is always higher than that of glucose, so sugary fruits would probably promote a higher thermic effect than starches.
    What is your opinion about "natural" sugars from fruits and "added" sugars? Are they the same thing?

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    I don't have a problem with sugar itself. But it needs to be accompanied by the appropriate nutrients, especially magnesium. Fruit tends to provide those nutrients. Processed foods with refined sugar do not.

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    Quote Originally Posted by Elliot View Post
    I don't have a problem with sugar itself. But it needs to be accompanied by the appropriate nutrients, especially magnesium. Fruit tends to provide those nutrients. Processed foods with refined sugar do not.
    What would happen if you have a diet that was 400 g protein, 0 g carbs, and 0 g fat. Is such a diet even possible? Is this basically a PSMF (protein sparing modified fast) with more calories? Is it healthy?

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    Quote Originally Posted by ifguy12 View Post
    Is it healthy?
    No! Look up "Rabbit starvation"

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    Quote Originally Posted by Elliot View Post
    No! Look up "Rabbit starvation"
    But would you advocate a 200 g fat, 0 g carb, 0 g protein diet for ketogenic purposes? Is this better than the PSMF described above?

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    I would advocate a diet with protein, carbohydrates, and fat in appropriate proportions.

    Why do you want ketosis? Are you epileptic?

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