The 5:2 Diet/Fasting Plan revisited

Published first on 7.9.2024 republished 8.13.2026: A long time ago (but not in a galaxy far, far away…) my husband and I did the 5:2. We did it because we both needed to lose weight, and it worked for us… at least while I was doing the cooking. It's not a true "diet" or true "fast" and it was popularized by Michael Mosley (may he rest in peace).

It's not a true diet because there are no foods that are restricted, and it's not a true fast because there's never a day where you don't eat. Instead, the plan calls for you to eat normally for five days a week, and then for two days to restrict your calories to 800. An easy way to do this would be do just drink protein shakes on the days where you're restricting, but this isn't how we did it. I would simply devise meals that would add up to 800 calories for the day. Alcohol is not forbidden, but it's difficult to keep to 800 calories if you're drinking alcohol.

I enjoyed it; my husband did not. I wonder if it would have been easier for him if we'd just done the shakes, but the only reason I got him to try it was because he could still eat "real food." In the end, when I started working outside the home and he took over cooking, the 5:2 went out the window. As did any weight loss we'd achieved.

He does NOT consider calorie content when he cooks— and believed that saturated fat was the liquid fats in bottles. I've told him he got it backwards, but I'm not sure he believes me. He cooks almost exclusively using saturated animal fats… he's only started occasionally using vegetable (olive oil or soy oil) because I complained that my cholesterol skyrocketed under his cooking. I do NOT cook with animal fats for the most part, mostly because of the cholesterol effect.

Lately we've been discussing his taking Ozempic (though our insurance won't cover it because he doesn't have type 2 diabetes) or Wegovy (I don't know if they asked about that) to try and lose weight and hopefully drink less. Sometimes I feel like I'm watching him kill himself. He won't work out at the gym… and actually at this point, I'm not sure what he could do at the gym because he can't stand for very long. But my husband's health is not why I'm writing this piece, or thinking about doing the 5:2 again.

This piece was inspired by this video on YouTube, which discussing the results of a study that considered the effect of the 5:2 on people with type 2 diabetes. If Michael Mosley were still alive, he would have been all over these results, as they were quite positive for the 5:2. I don't have type 2 diabetes, so that's not why I'm considering following it, but I would like to lose weight a bit faster. I am (slowly) losing weight as I continue to work out at the gym three days a week, but I think if I severely restricted calories on the two days between gym sessions I would make better progress. It's worth an attempt. Any further benefits that accrue (and the research on the 5:2 suggest that there are some) would be a bonus.

Gym days and weekends would be unaffected, but on Tuesdays and Thursdays I would likely wind up skipping lunch and limiting alcohol. My daily breakfast, which is a high protein, calcium rich pudding that I make rather than taking a calcium supplement has about 300 calories in it, and it's reasonably filling. If I save the rest of the 800 calories for dinner, I should be able to eat a normal (if smaller) dinner of food. If I decide to do this I should probably mention it to my husband. My biggest concern is getting enough protein in the remaining calories at dinner so that I can work out fasted the next morning.

I work out fasted by necessity. I basically wake up and head out to the gym. If I eat (even just a banana) I find that my stomach regurgitates a small amount of the food. If I work out fasted, that doesn't happen. Typically, I eat enough at dinner that it's not a concern. If I'm limiting my calorie intake, that might not be the case. Of course, this might all be in my head too… it might not make any difference. 500 calories or so is a sizable meal (though perhaps not in the USA). I think I'll just have to try it and see how it goes. If I expect there to be no issue, there probably won't be. I do think that mindset plays a huge role in "hunger" if the person has eaten in the past 24 hours. That's not to say that the body won't crave more food, just that it's not in danger of expiring that quickly. And I typically eat as soon as I come back from the gym, and on gym days I wouldn't be restricting at all.

My current diet is to prioritize protein (both plant and animal) and fiber (which means fruit and vegetables plus a bit of whole grains). It irritates me that whenever fiber is discussed the category of "whole grains" is put before fruits and vegetable. Probably because getting a ton of calories from fruit and vegetables is harder than from grains. Beans are never mentioned. But I'm a volumetric eater (I like to feel full) so eating a lot vegetables, fruit and beans is probably the best way to go for me.

I didn't set out in the piece to convince myself to do this, but I think I have. I think I will start a new 5:2 adventure, where I skip lunch on Tuesdays and Thursdays and then have roughly 500 calories left for dinner and any alcohol that I want to drink. Limiting alcohol on those days won't be a bad thing either.