Q & A: How often should I have a cheat day if I am trying to lose weight?
A: Never. I am not saying that I expect you to eat perfectly forever, but I am saying that the idea of cheat days needs to die 
.
What’s a Cheat Day?
Let’s agree on what exactly a “cheat day” is. A “cheat day” is the idea that you eat like an adult 6-ish days per week and then just eat whatever the remainder of the week. At the end of the cheat day you go back to eating like an adult while waiting impatiently for your next opportunity to stuff yourself.
In other words, cheat days are binge eating without the purging.
Cheat days became a thing in the 90’s because they were promoted by bodybuilders turned supplement marketers. Ironically the bodybuilders promoting the cheat day concept used 16-20 weeks of aggressive dieting (no cheat days for them!) + drugs + 12-20 hours of exercise per week to prep for the photo-shoots to promote the books that promoted cheat days.
Reality Check: Everything Counts
If you do adult eating for 6 days, and build up a 3,000 calorie deficit, you should be proud of your hard work. You should also know this whole deficit (and more) can easily be erased with one McGriddle (450-550), one Java Chip Frappucino (440), and a dinner out with wine (200-ish per glass), appetizer (400-ish if you split), main (900+) and dessert (450+). Is this unfair? Definitely. Does this unfairness change reality? Not at all.
A magic calorie sucking vortex that opened up on cheat day and allowed you to eat whatever would be amazing. Being a few inches taller, and finding the winning lottery ticket in my wallet would also be amazing. If wishes had wings we’d all have nice things, (and nothing nice would ever be special again.)
Metabolic Boost?
There’s a book series and plenty of articles on the internet that will tell you how having regular “cheat days” will boost your metabolism and/or enhance fat loss. Some even talk about how the cheat day will boost your leptin levels, and that since leptin has a little something to do with your appetite and energy expenditure the binge eating will make it easier to lose weight. This is pure bullshit.
First of all there is math. If, on a cheat day, you eat away the deficit you have worked all week to create the net result is no weight lost.
Second is the very misleading “metabolic boost” claim. We do burn calories to digest our food, and this is misleading when presented in terms like “the more you eat the more you burn.” While eating more total food means burning more total calories in digestion, it’s still only going to be 10% of the increase in calories eaten. This means you’re absorbing 90% of this increase. So, you burn more, but you also absorb 9x more.
Third is that boosting leptin really isn’t very helpful for weight loss in humans. In mice that have been engineered to not make any leptin, it’s a game changer, but we’re not even the same species. In overweight humans leptin levels are actually very high, and the problem is the brain not responding to it (leptin resistance). Overeating actually makes leptin resistance worse. In other words, cheat days make this worse.
Bottom Line
I am saying what economists have said for centuries: there’s no such thing as a solution, only tradeoffs. It’s also what your grandma said: if it sounds too good to be true, it is.
Here are some ways to take action to enjoy your favorites and still lose weight:
· How to have your wine (or other favorite things) and drink it too.
· A very important way to burn more calories.
· Simple ways to reduce your calories.