Reader question: Is alternating between high- and low-calorie days a good idea?


If I eat 21,000 calories a week evenly at 3,000 per day, would I weigh the same as if I alternated between good days (1,500 calories) and bad days (4,500 calories)?

– Wondering in Wimbledon


Hmm … This seems like an experiment that must have been done, but I can’t find evidence of it anywhere.

I’m guessing here, but I think that in this specific example you would be worse off on the alternating plan. Assuming you are an average-sized person, 4,500 calories is quite a lot and is likely to stress your metabolic pathways and lead to inflammation, while 1,500 calories probably isn’t few enough to elicit any of the benefits of intermittent fasting.

But if you had asked the same question with fewer overall calories, say 2,000 per day, then you would be in a typical intermittent fasting regime and alternating between ‘good’ and ‘bad’ days might have some benefit.

I should also say that you shouldn’t worry too much about calories. If you stick to unprocessed foods, the calorie side of things should take care of itself.

So if alternating between ‘good’ and ‘bad’ days somehow helps you stick to unprocessed foods, then go for it. But if it makes it harder for you to stick to unprocessed foods then it’s not worth it.