We all know that about 3500 calories is equivalent to 1 pound (7500 cals for 1kg).

So can a piece of food weighing one pound have more than 3500 calories?

What are the highest and lowest energy dense foods? and will consuming the former make you less full while the latter make you feel fuller for less calories? or do the calories consumed cause you to feel full?

Is there a limit to how many calories can be in 1 pound of food (including artificially made "foods")?

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    Hi Aequitas, thanks for joining and asking. Your question begins by this statement: "We all know that about 3500 calories is equivalent to 1 pound (7500 cals for 1kg).". I don't know whether this is true or false, but as it is an assumption your question is based on, it should be documented. If there is no way to document it, the question should be whether this is a valid assumption. – Shlublu Apr 30 '15 at 23:10
  • I'm not sure what you mean, those numbers are commonly used everywhere for that amount of weight loss/gain. Besides the exact numbers are irrelevant, another phrasing of the question could be assuming zero calories burnt (including from breathing and such) could you gain more weight than the weight of what you are consuming? Does that make sense? or If I see "X" on the scale, can my weight only go down assuming no consumption of food or water? – Aequitas Apr 30 '15 at 23:27
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    @Shlublu - health.stackexchange.com/questions/797/… – JohnP May 1 '15 at 2:13
  • Duplicate :skeptics.stackexchange.com/questions/2688/… – Kenshin Jun 30 '15 at 8:12
  • It is possible, not directly, but rather indirectly by the byproducts that the foods attract. Eating more carbs will cause muscles to store the carbs as glycogen. Glycogen makes muscles store more water. The water retention added on to the carbs that are stored might way more than the food that brought in the carbs, although I have no empirical evidence for this. You might hear people talk about dropping 2 pounds in a week because they lowered their carb intake. What really happens is they lost mostly water weight, not fat. Total caloric deficit determines meaningful weight loss. – JoJo Feb 1 '16 at 5:24

You seem to be equating food weight with body weight, and they are not directly related.

Yes, if you eat a pound of something, you will immediately weigh one more pound, as your body has not had a chance to digest it and process it as needed. However, that doesn't mean that you will have gained one permanent pound. The body will break down the food, distribute the end result to various places for either use or storage, and get rid of whatever is not digestible.

Weight fluctuates during the day, so the best gauge of your weight is to weigh yourself at the same time every day, under the same conditions. Track that number, and that gives you your true weight.

Also, weight gain/loss is a relationship between how many calories you need to sustain your day to day activities, and how many you eat. If you consistently eat more calories than you need for a day, then you will gain weight. If you consistently eat less, then you will lose weight. The rate at which you do so varies on how big the deficit/surplus is, how efficient your metabolism, type of calories, many factors such as these.

For your main question, 3500 calories per pound of food is very calorie dense. For example, 1 lb of peanut butter is going to be ~ 2600 calories. The higher the fat content, the closer you get to that mark. If you ate a straight pound of fat, for example, you would get just over 4000 calories. (Using the typically accepted 9 calories per gram of fat, which is also not 100% accurate). So yes, it is possible to get more than 3500 calories in a pound of food.

  • So say you weigh 100 lbs you eat 1lb of fat which has 4000 calories, your body breaks down what you ate and turns it into energy to use in various things such as making body fat (and muscles and what not) and you could end up (ignoring all other bodily processes) weighing over 101 lbs? right? ie. your weight will increase as your body processes this lb of fat. – Aequitas May 1 '15 at 1:31
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    @Aequitas, by the law of conservation of mass, you can't gain more weight than the weight of the food + water you consume, and you will usually gain much less weight than the weight of the food you consume. – Kenshin May 1 '15 at 12:22
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    @NinjaDoc I was going to invoke the laws of physics too but then it occurred to me that food A could potentially cause the body to absorb and store food B more readily than it would without food A. I know of no examples of such a food, but I suppose it's possible. – Carey Gregory Jun 18 '15 at 18:33
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    @CareyGregory - There are nutrients and macros that enable and enhance (as well as detract) the absorption of other nutrients. One prime example is that in a completely fat free diet, you will run into vitamin deficiencies as there are vitamins that rely on fat for transport (fat soluble vitamins). – JohnP Jun 18 '15 at 18:55
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    @NinjaDoc - The same reminder. Comments are for clarifying a question or answer, not arguing with another user. Please move this to chat, as I will be deleting the comments once both parties have had a chance to review. – JohnP Jun 30 '15 at 14:47

Kind of. Oils/fats/alcohol has 9 calories per gram. 1 pound is 453.593 grams. 9 x 454 = 4,086 calories. So eating 1 pound of oil will give you 4000 calories. However, you will be unlikely to keep all that oil in your digestive tract!

Eating hygroscopic foods will also make you 'gain' more than they weight, because they will attract water. Eating honey or lots of fiber will absorb water and 'appear' to gain weight while it's in your intestines, but you'd also have to drink liquids.

  • Do you have references to support your assertions? – JohnP Feb 1 '16 at 2:08
  • @JohnP Added references. – Chloe Feb 3 '16 at 22:30

Forget calories and energy for a moment. The only thing with mass(weight,on earth) are atoms. When you weigh yourself, you are measuring the number of atoms you have(in pound units)in and on your body. The only way for atoms to enter your body is through ingestion, inhalation or absorption through the skin. The only way for atoms to leave your body is through urination, defication, sweat, exfoliation of skin, and exhalation. Atoms absorbed or lost through the skin are not a significant source of permanent, or long term, weight gain or loss. So, the only way to gain more atoms (weight) than you eat through your mouth must be from the inhaled air. The only significant inhaled atoms are molecules of oxygen (O2). The only significant exhaled atoms are molecules of carbon dioxide (CO2) and water (H2O). Unless my logic is faulty, because molecules of CO2 and H2O have more atoms than O2, breathing is a net source of weight loss for the body. I would argue that the atoms of carbon in the exhaled CO2 are the primary way the body loses weight when on a diet! The other significant pathway that atoms are lost from the body would be through the atoms of urea, CO(NH2)2, excreted in the urine. The atoms in digestive enzymes and bile are removed from the body in feces. However, I do not know if this is a significant source of atoms leaving the body.

In conclusion, I do not think it is possible to gain more body weight than the weight of the food you consume. I will add that water confuses the issue. It enters and leaves again in a variety of homeostatic mechanisms.

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    Please do add some references – L.B. Aug 1 '17 at 18:54
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    As @L.B. says, references supporting your atoms assertion would be great. I can say with great certainty, that if your daily caloric needs are 2,000 food calories, and you consistently eat 3 pounds of food with a caloric count of 4,000 calories you will permanently gain much more than 3 pounds. (Not the day to day fluctuation, long term permanent weight gain will ensue.) – JohnP Aug 2 '17 at 2:55
  • I am not sure which of my assertions require references. Much of what I stated is basic biology and logic. However, if you will identify any questionable assertions I made, I will endeavor to provide a reference. A couple of laws I used, but did not state: 1. Mass(atoms) cannot be created or destroyed by chemical or physical changes in the body. The atoms can be rearranged into different molecules, but their number and type(atomic #) does not change. 2. In the absence of nuclear fission,fusion,or interactions with dark matter, mass is not changed into energy and energy is not changed into mass – Ray L. Aug 2 '17 at 20:59
  • JohnP. I think we are in complete agreement. Where things become cloudy is that not all molecules store the same amount of energy. If I eat a pound of digestible protein or digestible carbohydrate, I am ingesting about 1816 calories. If I consume a pound of digestible fat I am getting about 4100 calories. If I need 1816 calories/day of energy to perform all of the endothermic reactions in the body, then I would need to eat either 1 pound of pure protein/carbohydrate per day or a little more than 1/3 of a pound of pure fat. So, If I ate 1 pound of digestible protein carbs/day, my weight would n – Ray L. Aug 2 '17 at 22:22

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