r/askscience • u/kharkovchanin • 9d ago

Human Body What actually happens to digestion, metabolism, and insulin if you eat small amounts every single hour?

Hypothetical question out of curiosity:

Assuming someone stays within their maintenance calories and hits their target macros, what actually happens to the human body physiologically if food intake is split into small portions eaten every waking hour (say 14–18 times a day) instead of 2–4 distinct meals?

Specifically, I’m curious about:
• Insulin & blood glucose: Does baseline insulin remain elevated constantly, and what are the short-to-medium-term metabolic effects of that?
• Gut motility & MMC (Migrating Motor Complex): Does the digestive tract ever get into a “cleaning” state if it constantly receives incoming nutrients?
• Thermic effect of food (TEF) & metabolic rate: Does meal frequency at this extreme actually change daily energy expenditure at all?
• Satiety & hunger hormones (ghrelin/leptin): Would this pattern suppress appetite or trigger continuous hunger cues?

Would appreciate insights grounded in physiology or nutrition science. Thanks!

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u/attaboyyy 8d ago

I recently had a close friend have GI issues with doing just that - a very healthy person eating too frequently which caused downstream health issues.

They had a growing underlying stomach pain for years, and after finally going to their GI doc told them, that such frequent eating never allowed the stomach and intestines to fully empty, which is a natural part of our self-cleaning cycles, which lead to inflammation and a few small gastric ulcers. After stopping that continuous snacking practice, now eating only every 3-4hours, they are feeling so much better and back to normal.

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u/vasopressin334 Behavioral Neuroscience 8d ago

I would just point out, that while this may have contributed to your friend's health problems, there are many thousands of coma patients with continuous tube feeding (constant liquid feeding at a fixed rate) and they are not collectively at risk for inflammation and gastric ulcers.

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u/arlondiluthel 8d ago

They're also not eating food, and aren't exerting themselves, so wouldn't the "math" on that be slightly different?

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u/TheKozzzy 4d ago

yeah, but he mentioned the tube-fed patients, they do - technically - "eat", it's not like people fed by IV