Maximum Meal Size

Hey Folks,

My nutrition knowledge is little more than parroting what I read off the internet, but I was curious if anyone could expand on a question I’ve been thinking about.

Based on my understanding: if we overconsume in a period of time, the excess carb or protein gets stored as fat. So while on some big days, we are probably better off over consuming just to get the calories in, on most days, it makes more sense to eat over a period of time (first question - is that really true?). Continuing with this - what is the +/- maximum grams of carbs and protein one can absorb per meal?

Great to hear any comments or thoughts along these lines. I’m trying to better space our my meals so as not to overeat at dinner. I can eat an amount of food that I think would make @Nate_Pearson blush. (I tagged Nate because I think he’s done the math on this and am curious what answers he got…)

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Eat only when you’re hungry, when you have that hungry feeling in your gut. Eat enough to not be hungry. Do NOT eat until you feel full or stuffed. If it’s lunch time and you don’t have that hungry feeling, you ate too much at breakfast and/or prior to lunch. Same for dinner relative to lunch. Adjust how much you eat each meal until you find yourself hungry when the next meal time arrives. If you find yourself really needing a snack, grab something like a piece of fruit.

During your workouts, fuel them. Doing so increases the quality, reduces RPE, helps with recovery, and also helps w/preventing you from eating everything in sight afterwards.

And of course, eat high quality nutrient dense foods. Yes, you can occasionally eat chips, cake, etc… but it really needs to be occasionally and not regularly. Be honest w/yourself! Don’t tell yourself, I did a workout today so I can eat this cheesecake. NO, you have to do the workout and not eat the cheesecake. That’s how the weight comes off :grinning_face_with_smiling_eyes:

Don’t get too hung up on your weight itself. If you focus on the training and even part of what I said above, you will get fitter/faster and the weight will take care of itself.

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Not really on topic? I guess it’s a comment along these lines, but I was hoping for more specific numbers not a general tonic on healthy eating…

I don’t think this is the right way of looking at it. At short term, it’s pretty well understood that your body can only utilize some maximum amount of carbs per hour. However, on the long term, I believe it’s more about calories in vs. calories out. If you eat more calories than you burn, the excess is stored. That would not happen as a result of one meal, however a single meal can have so many calories that your excess calories may be hard to overcome. Some may quote that 50 or 100 grams of protein is a good goal per day or 250 or 350 grams of carbs, but that is dependent on how much your burn as well. If you burn 2000 extra calories in a day, you will need to replace that with a lot more than 250 grams of carbs.

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I’ve been wondering something similar.

I haven’t found anything showing the maximum amount that can be absorbed at once but have seen that the rate of absorbtion ( and amount ) will decrease with as you increase both fibre types in the meal as well as the protein in the meal.

Hope this helps.

Sorry my reply wasn’t exactly what you were looking for, but I didn’t give exact numbers or even rough estimates because:

  1. “maximum meal size” is going to vary per individual and activity level
  2. you can find an endless number of published papers w/varying numbers which can differ significantly
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It just isn’t as simple as assigning maximum meal size by how much the body can absorb at once as some foods are broken down and absorbed faster than others. For instance, eat a piece of toasted white bread all by itself and it will be absorbed very rapidly. Put some butter on that piece of toast and the digestion is slowed as the body also has to deal with the fat within the butter. Now add 2 eggs and a piece of bacon to the buttered toast and the digestion is slowed even further, meaning the absorption may take a few hours.

I’ve had this exact question. I don’t think I know the entire answer but there are some holes filled in by research.

My goal is maximum carb loading and muscle repair with minimal fat gain.

So here’s what I’m pretty confident in.

  1. For calories matched, your weight will be the same if you spread it out or take it all in during a small window. There’s been some research on fasting looking at this.

This doesn’t answer the body comp question though.

  1. People who fast can get all of their protein during the eating window and have the same strength and size gains as people who spread it out.

This is from more fasting research. It’s also nice thay we don’t have to do like 6 meals with protein spread out over the day. This was the trend in the early 2000s and I did it myself. It was a pain.

What I don’t know off the top of my head is how body comp is impacted in people who fast vs people who doesn’t when calories are matched.

I believe I read that body comp also didn’t change…but don’t quote me on it, I could be wrong.

My thought right now is to not worry about it. But if I do consume protein I want a bolus of at least 20 grams.

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Thanks for the comments. I was also looking at fasting research (not about fasting but similarly about how much is “useful” or “not useful” to eat in one sitting - and for similar reasons).

I’m 73kg and try to eat up to 2g of protein /kg/day, which isn’t all that much. I’ve read 20gr per meal as more of an upper limit (as in, if you eat over 20gr, it’s probably not getting used). So I was wondering if perhaps spreading it out to some extent isn’t a smarter move.

Something similar is at play with carbs, where I’ve often read a 100gr upper limit (per hour, not per meal).

All that said - a lot of the fasting research shows neither gains nor losses from loading up in a fixed time. I wonder if increased exercise would change it, but I’m also glad to know my evening gluttony isn’t having horrible effects.

If I recall correctly, this was based upon protein uptake, but didn’t take account of the other factors as to what the protein was eaten with. Like @rthompson is saying, only swapping carb uptake with protein uptake.

Surely the carb part of this question at least depends quite a bit on what state your glycogen stores are in when you eat that meal? Your body can store ~2000 calories of glycogen in the liver and skeletal muscles. If those stores are already pretty full and you eat a big meal then the body has nowhere to store those calories as carbs, so it’s got no option but to start converting them into fat storage instead. On the other hand if your glycogen stores are depleted (e.g. you’ve been exercising and/or fasting) then the body’s first priority is to replenish those stores.

Other thing to consider is what kind of foods you’re eating and what you’re doing after that meal. E.g. if your glycogen stores are fairly full, you eat something slow release like porridge and then go for a ride, then as those calories become available your body is going to be using them to fuel the workout (unless you’re working out at a high enough intensity to impair digestion, but that’s a whole other topic!) rather than storing them as fat. Whereas if your stores are full, you eat something sugary and quick release for dinner and then go straight to bed, then those calories are going to be hitting you in a big rush at a time when your body has no use for them and will therefore be working overtime to store them as fat (also going to mess up your sleep quality).

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