Training & Nutrition - Calories In - Questions

A few questions I've got, hoping the really informed amongst you can get me some info. Before I start, I'll state that I am not a calorie counter. I bike about 200 miles per week, run around 30 and have dropped about 40lbs in the last two years. Lots of people around me are calorie-counters now and there's a few questions I have:

- Who calculates the calorie totals that are marked on food labels? Is it the company that is selling the food, or is there an impartial outside tester?

- 3500 calories equals one pound. But food items that weigh one pound don't have 3500 calories in them. For instance, I've seen a McDonald's Quarter Pounder listed as 420 calories. So for instance, let's say someone eats 4 of those (for simplicity let's ignore the fact that with the bun it'd weigh more etc.)
That's 1680 calories, but the food weighed one pound. That person would weigh one pound more immediately after eating the 4 burgers. Of course, over time much of that will be discarded in bowel movements and the person doesn't actually gain an entire pound. So the calories (1680) are considered the amount that actually will be absorbed into the body. But my question is, won't different people discard or absorb drastically different amounts of that pound of hamburgers? (due to tons of different factors) Therefore, aren't the number of calories themselves going to be different for different people?

Short answer:
Yes. But the differences aren't big enough to invalidate the method. And of course, you have the option of diverting from the guidelines any time you think you can profit from it.
You have to take these numbers as rough approximations.

I only keep track to make sure im burning more than im taking in.

I think food calorie counts can also be calculated based on standards for common ingredients. i.e. if a packaged food is 100g butter, 100g wht. flour, 100g sugar then package label is based on calculated 100g of each, all which have a standard known value, added up.

Al

The human GI tract is fairly standard-what exactly do you think would make one person "absorb" fewer calories out of the same burger? The only thing I can think of is if a person was suffering from food poisoning and it went straight through them, or if they had a tape worm eating the food instead of them.

Not to mention that of that pound, a significant portion is water weight. I'm not even going to try and explain how carbs and protien differ by weight than fat and therefore...blah blah blah, you can google it.

Some of it has to do with density as well. Fat = 9 calories per gram. Carbs only 4. A pound of stored body weight = 3500 calories, all of which is fat. Water weight, intestinal contents, clothing, etc are all highly variable. Consuming 3500 calories more than one burns does indeed result in the storage of 3500 calories worth or one pound of fat.

A calorie is not a "thing" that can be absorbed or not absorbed.
a calorie is a measurement unit of energy. On kiloCalorie (same as a calorie in nutrition) is the amount of energy required to raise the temperature of one gram of water by one degree. The calories in food are actually determined by burning the food and measuring the heat it puts off. For example, a Big Mac at 1680 calories would burn hotter and longer than a head of lettuce at 100 calories. Fat (9 calories per gram) will burn more than twice as long and hot as protein or carbohydrates.

Energy cannot be destroyed in the body. Energy that is not used is stored in the body as fat (mostly). 3500 calories worth of extra energy will be stored as one pound of fat. When one "burns" 3500 calories in excess of the food taken in, one will lose one pound of fat.

"- 3500 calories equals one pound. But food items that weigh one pound don't have 3500 calories in them. For instance, I've seen a McDonald's Quarter Pounder listed as 420 calories. So for instance, let's say someone eats 4 of those (for simplicity let's ignore the fact that with the bun it'd weigh more etc."

Yup, already been said about 3500 calories of fat = 1 pound. Also realize the metabolic efficiencies involved.

1. eat 1/2-lb of fat (1750 Calories).. say extra cheese creamy buttery alfredo sauce. Fats are absorbed straight through without any loss, so that 1/2-lb of cheese sauce becomes 0.50-lb of fat directly on your body...

2. eat a full pound of bread, an entire loaf 437.5gm = 1750 Calories. If it's even possible for you to stuff your face like that, and the entire loaf is digested and you sit around watching TV for the next 10 hours, that 1750 Calories of carbs is converted to fat with a 60% efficiency, the 40% is used up in the conversion process. So you end piling on 0.30 of a pound of fat by eating a full pound of bread...

The assertion here is that it's a lot easier to get more calories and pile on more body-fat by eating fats than carbs. Just from the energy density alone 2.25x as well as the greater density of fatty foods compared to bready stuff. Or if you compare roughly equal portions:

1. eat 1/2-lb of fat (1750 Calories).. say extra cheese creamy buttery alfredo sauce. Fats are absorbed straight through without any loss, so that 1/2-lb of cheese sauce becomes 0.50 lb of fat directly on your body...

2. eat 1/2-lb of fettucini (880 Calories) and you burn off none of it, you end up gaining... 880*60% = 528 Calories = 0.15 lbs from the noodles

Basically, in equal proportions, you end up gaining 3x as much weight form eating equal amounts of fats compared to carbs. This difference becomes even greater if you work out as intense aerobic exercise tends to burn of more carbs than fats. Strangely enough, recent research studies seems to indicate that weight-loss is proportional to calories/hour burned, regardless of intensity. So if you workout at a rate of 1167 Cal/hour, you're gonna loose 1-lb each 3-hours of exercise compared to someone else working at a slower pace of 500 Cal/hour; which would require 7-hours of exercise to loose the same 1-lb.

So I have a problem with the math here.

1 gram of fat = 9 calories
454 grams = 1 pound
454 x 9 = 4086

That means that 1 pound of fat has 4086 calories, not 3500. Could some one explain this?

The human GI tract is fairly standard-what exactly do you think would make one person "absorb" fewer calories out of the same burger? The only thing I can think of is if a person was suffering from food poisoning and it went straight through them, or if they had a tape worm eating the food instead of them.

Not to mention that of that pound, a significant portion is water weight. I'm not even going to try and explain how carbs and protien differ by weight than fat and therefore...blah blah blah, you can google it.


Thanks. It just seemed to me that differences in people's bodies would cause different amounts of food to be turned into waste. Since a couple people have stated with certainty that this really isn't the case, I'm satisfied that my assumption (not based on evidence, just what seemed right to me) was incorrect. Thanks for the responses.

So I have a problem with the math here.

1 gram of fat = 9 calories
454 grams = 1 pound
454 x 9 = 4086

That means that 1 pound of fat has 4086 calories, not 3500. Could some one explain this?

1 gram of consumed, edible fat contains 9 calories

Your body must burn 3500 calories to lose 1 pound of body fat. Two different processes, two types of fat.

Two different processes, two types of fat.

Gotcha, Thanks

Well, it's more like you lose 10% of the calories in converting fat into glycogen...