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# Weight of Food VS Calories ingested VS weight gain [Caloric Density Question]

Reposted from "Calorie Count" forum [hoping for more than 0 answers]:

Hi, I had a question about weight of food vs. weight gained.

So, if you eat one pound of cucumbers, it is approx. 60 calories.

If you eat one pound of sirloin steak, it's 850 calories.

A pound of butter is 3200 calories.

How do all of these equate to different amounts of weight gain? A pound of food doesn't equal a pound of weight gain (unless you're eating plain butter, apparently). I know that 3,000calories = 1lb.  What's up with this?  If I weigh myself before and after eating, I will have gained that pound of food weight, but at what point do the calories balance out? When will the pound of cucumber or sirloin equate to less than one pound of body weight?

I guess I'm trying to wrap my head around how calories are absorbed and what that extra weight of the food is - is it all water? How do we get rid of it? Or, with something like butter (where I wouldn't eat a pound, but it still applies in smaller quantities) - how does it equate to MORE than a pound of weight gain?

7 Replies (last)

A calorie is the amount of energy it takes to increase a gram of water by 1 degree.

Calorie density is the amount of calories in a gram of food.  Butter is high density, cucumbers are low density.

Right after you eat (or drink) you have the weight of the food in your body, regardless of the calorie density.  As you digest the food, you generate waste (urine and fecal matter) and energy.  The energy your body uses to fuel itself (work, maintaining temperature, keeping the heart beating, etc.).  Any excess gets stored as fat in your fat cells.

So, if you eat a pound of butter at 3200 calories, and your body only needs 2000 calories to function over the time period that you ate the butter, you would have 1200 excess calories that your body would use to make fat cells.  If you ate that same pound and your body needed 4000 calories, you would burn 800 calories of fat cells to meet your energy needs.

Wow, very interesting! I'd like to know the answer also.

I totally see what your asking. Like how does ingesting in weight < a lb of something high cal turn into more than a lb of fat? How does that weight turn into WEIGHT on us.

Interestingly, calories don't depend on the weight of the food. As you pointed out, a pound of butter (a fat) is not the same as a pound of bread (a carbohydrate). Each TYPE of food has a different amount of calories. Fat has 9 calories per gram. Carbohydrates and protein have 4 calories per gram.

So if you eat a pound of butter (fat), you've got over twice the amount of food energy (calories). If you eat the bread (carbohydrate) instead, you will gain less than half the weight!

Another way to look at it is if you take the fat off your steak (a protein), you can eat the same amount of weight of more steak and still be saving calories, lol.

Also interesting is that people tend to eat the same bulk (volume) of food, so given that, if you eat more carbs and protein and less fat you'd loose weight just with that change.

The main thing is to keep an eye on the total calories. If I overeat, I can actually predict my weight gain to .1 kg the next day based on my calorie intake vs. my activity level (calories burned).

And oh yeah, a lot of foods have a lot of water weight, which has zero cals. So if you eat, say, a pound of bread vs. a pound of dry toast, you're more calorie dense with the toast.

If you have a good biology book check out the cell energy cycles. Very interesting.

You'll even see that the air you breathe also gets incorporated into things.

Thanks for all of your responses. It's becoming more clear - I have to imagine that I had learned this at some point (HS Biology, perhaps?) - but I think I will check out a textbook for additional clarity.

:D Thanks again.

Original Post by iheartalmonds:

Like how does ingesting in weight < a lb of something high cal turn into more than a lb of fat? How does that weight turn into WEIGHT on us.

There is NOTHING that will make you gain more weight than it weighs.  The "worst case scenario" would be consuming a pound of oil/fat over and above your calories burned that day.  That would turn into a pound of fat.  (And nobody would ever do that because it would be really really gross.)

Whenever you eat (or drink) a pound of food (or drink), you will instantly weigh 1 pound more on the scale because the scale doesn't just measure you.  It measures you plus everything in and on you.  So, eating that pound of food is like putting on a pair of shoes that weigh a pound.  The scale says you're heavier but it's not really you.

Most of the time, only some of the weight of that food contains usable energy, and the rest is filler like water and fibre (necessary things for health, but the body can't extract (much) energy from them).  The filler passes through your system and doesn't contribute to energy needs or fat storage.  The rest can be broken down to generate energy for your body, and if there's more than necessary, it'll get reassembled into fat (no matter what kind of calories they started as) but the fat will weigh less than the stuff from which it was made because bits of it get lost in the process as carbon dioxide and water (that you exhale).

The above paragraph is a bit of an oversimplification (so the science junkies don't need to jump all over me) but it gets the point across without going into too much technical detail.

"There is NOTHING that will make you gain more weight than it weighs.  The "worst case scenario" would be consuming a pound of oil/fat over and above your calories burned that day."

Ok, so 1lb = 453 g of fat * 9cal/gram (plus conversions...)

(453 g) * 9 (cal / gram) = 4077 calories;

I was recently informed that it takes 3500 calories [not 3,000 as I had stated] to equal 1 lb.

Thought I had it, but now I am confused...

Thanks for you pseudo-scientific reply, susiecue.

7 Replies