Can you do reverse 5:2 fasting? Essentially 2:5?

cecsav1

My job requires long hours, is stressful and exhausting, and leaves me little time, energy, or desire to eat regularly. Would there be any reason I couldn't eat at 800-900 calories per day throughout the week and increase my calories to 3000ish per day on the weekend when I'm home with my kids? Would this cause any long term damage or health problems?

SideSteel

I'm not aware of any evidence that it would cause long term damage but I suspect some things would happen:

1) It's possible that this could develop somewhat unhealthy eating behaviors because you'd likely develop some pretty intense food focus, high levels of hunger, fatigue/etc during the week. Then, you'd enter the weekend where you've got a pretty impressive calorie target, you'll be hungry and thinking about food because of a week of very low food intake, and it wouldn't surprise me if you have a hard time sticking to your calories on the weekend.

I'm largely speculating here, so I don't mean to paint this grim picture but I could easily see this happening.

2) You might have a hard time sticking to the low days at least in the way you've outlined them.

3) You'd likely not optimize retention of muscle mass with that large of a deficit during the week.


Now having said that ---

I DO think there's merit to an approach where you look at lifestyle and attempt to leverage calories towards that. So for example if you have an easier time sticking to a deficit during the week, that's good reason to consider something SIMILAR to what you're attempting. I just wouldn't separate the high and low days by this big of a margin.

If it were me, I'd consider setting intake on weekends to maintenance calories for 2 days, followed by creating a deficit the other 5 days during the week but set that deficit according to roughly 20-25% under TDEE when you average it out over all 7 days.

Example: Suppose maintenance is 2000 calories. A reasonable deficit could be around 1600 calories if you did this daily. That's a WEEKLY deficit of 2800 calories

Set 2 days at 2000
Set 5 days at 1440 (<---- these 5 days bring you to a deficit of 2800 over the week)

Finally, let me reiterate that I think your idea has merit, I just think the differences between weekday and weekend eating are HUGE in your example, and the end goal here in addition to calorie control should be to set up reasonable food related habits/behaviors if the goal is long term success. At least some amount of consistency might be beneficial for this purpose.

DebSozo

Part of the success of 5:2 is that your stomach shrinks on the 2 light days, and you aren't as hungry on the other 5 days where you are eating TDEE. If you starve yourself for 5 days and binge on the 2 weekend days you aren't really teaching your body how to ease into maintenance for the long term, IMO. You aren't supposed to be eating a lot on the feed days.