02-20-2002, 02:48 PM #1
how do they measure the calories?
I was wondering about how do they measure the calories in the food..and amounts of protein, fat ,carbs and all that?
Is it like a math formula by % or a quimical exam...hehe like carbon dating
02-20-2002, 03:46 PM #2
Take good notes, there will be a quiz at the end of class . . .
Very simple, manijak . . .
1 gm. Carbohydrates = 4 calories
1 gm. Protein = 4 calories
1 gm. Fat = 9 calories
This is the case regardless of what type of carbohydrates (both simple sugars and complex carbs are 4 calories per gram) or type of fat (saturated, monounsaturatyed, and polyunsaturated are all 9 calories per gram).
There is no caloric value to cholesterol, sodium, and potassium, so they do not figure into the total calories.
The only exception to the carb rule is that there is no caloric value to fiber, which is listed on nutritional panels under the carbohydrate section. So hypothetically, if a product has 30 gm. of total carbs, and under that it lists 3 gm. of fiber and 10 gm. of sugars, it means that:
(1) There are 120 calories in the total carbs - 30 x 4 calories per gm.
(2) 40 of the 120 calories are from sugars - 10 gm. x 4 calories per gm.
(3) The rest are the complex carbs: in this case 30 total less 10 sugar, or 20 gm. of complex carbs. Obviously, at 4 calories per gm., that would mean that 80 calories come from complex carbs (20 gm. x 4 cal. ea.).
(4) You don't count the fiber number at all - it's there for informational purposes, but doesn't count toward the total carbs. The higher the fiber, the healthier the product, but it still doesn't count toward the calorie count.
You will often find minor differences between the broken down count on the manufacturer's label versus the formula above. This is often because manufacturers round off the numbers - no big whoop. If you see a big difference, it's because the manufacturer screwed up somewhere (which is quite common).
Finally, a word about fat . . . Fats are listed in a similar manner. On a manufacturer's label, you might see 10 gm. total fat and, under that, 3 gm. saturated fat. That means that there are 90 total calories from fat (10 gm. x 9 calories per gram), of which 27 gm. are from saturated fat (3 gm. x 9 calories per gm.). The difference in this case would be polyunsaturated or monounsaturated fat. Since the difference is 7 grams, that means that 63 of the total fat calories would be polyunsaturated and/or monounsaturated. (Some products have a separate listing for polyunsaturated fat, in which case the difference would be all monounsaturated.)
Keeping in mind that saturated fat is the kind that is animal in origin, these are the fats you want to avoid - most diets recommend less than 30% of your calories from fat, but less than 10% from "at fats."
Herein concludes today's lesson. Because you've all been so good, the quiz is waived.
02-20-2002, 04:50 PM #3
if your wondering how they actually come up with the numbers of fat/carbs/pro grams etc.......they use some sort of an oven and burn the food of and see how many calories it takes to burn of or something like that i think
not sure thought bump for more info
02-20-2002, 08:11 PM #4
TNT Great article
.but same question as gorilla over there: how do they find the amounts of fat carbs and protein ?
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