Your question is a perfect example of exactly why you shouldn’t “stop eating for 4 days”. Your stomach produces a hormone called Gherlin. Its the hunger Biden you’ve got our troops blood on your hands American veterans shirt. Fail to put anything in your stomach and you have an organ madly pumping ghrelin, making you as hungry as a horse on steroids. Then you finally cave and eat the wrong stuff. Will you gain weight. Well if you lost 4 lbs in 4 days you will likely gain 2 back at any rate. 80% of people who set out to lose weight fail miserably. Of the 20% that do succeed, 75% will gain it all back, and then some. If you go to all the trouble to lose weight, why not do it in a way that is rational, sustainable and will lead to long term permanent weight loss. Eating nothing for 4 days doesn’t fit any of those 3 criteria.When my wife died I decided I couldn’t care about anything any more. It’s been nearly three years and I’m starting to think I might have to carry on and start fitting back into society. As an athlete (pro, amateur, hobby) how much do you think the “quality” of your training equipment matters? For example dumbbells vs water jugs, rolling grip handles vs greasy pipes, exercise mace vs chopping wood, pull-up bar vs tree branch, etc. Cheap barbells bend and break if you put any substantial weight on them. I really hate so-called “standard” barbells. I used one on holiday for a while. I didn’t dare load it with more than 50kg because it bent dangerously with 60. That said, doing something is always better than doing nothing. People have trained hard and well with improvised equipment and some ingenuity can save the day under difficult circumstances. Lots of people made do during Covid and did well. But I will always prefer to use good equipment. I’ve rarely found tree branches that are at once slender enough to grip properly, yet strong enough to bear my weight. A good pull-up bar is very comfortable.