“Protein Makes Me Gain Weight The Next Day”

[This post replaces an earlier post which had an error in the spreadsheet data].

A common complaint I see on the Internet is

“When I eat more protein my weight goes up the next day.”

I rarely see anyone dig deeper into the question of whether higher consumption of protein actually causes greater weight gain the next day spread across time. A single day doesn’t say much about the effect of protein on weight.

A lot of days of eating protein

I have the last 150 days of data from Cronometer so I looked at how much my weight goes up the day after I eat protein. This is a chart of protein consumption compared to weight change on the following day.

A couple of things to note about this graph:

  1. The diagram is a scatter diagram.
  2. The Y axis is weight change between two adjacent days. Day to day weight fluctuations are all over the place.
  3. The X axis is grams of protein eaten the day before the weight change.
  4. The data is all over the place.
  5. The data appears to increase somewhat. More protein should on some level correspond to more weight gain (or less weight loss) since it’s more calories.
  6. The red line is the trendline that EXCEL determined.
  7. The trendline is a 3rd order polynomial.
  8. The deviation from the trendline is really big.
  9. The trendline shows that under 190 grams of protein (a whole lot of protein) results in weight loss (on the average).
  10. My weight is currently around 167 lbs.
  11. About 190 grams of protein results in weight stability (a bit over 1 gram of protein per lb of my weight).
  12. More protein than 190 grams results in a very small weight increases all the way to over 30 grams of protein.
  13. Very low protein (less than 100 grams) results in the most weight lost. It is not clear what the nature of this loss is from this chart. Is it more lean body mass lost? Is it just the low calorie amount for the day?
  14. I don’t have any very low protein data since I think it’s a serious mistake to undereat protein.


Protein, up more than 1 gram per lb of body weight did not result in average day-to-day weight gain.

Your mileage may vary. I am not sure how it could vary by much, but it may.


Author: Doug

I'm an Engineer who is also a science geek. I was pre-diabetic in 1996 and became a diabetic in 2003. I decided to figure out how to hack my diabetes and in 2016 found the ketogetic diet which reversed my diabetes.

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