You could just...eat less food. It's a lot easier.
Lyle's PSMF is also only ~11 days. You could seriously die doing a 28 day if you're not carefully supplementing with vitamins, minerals and electrolytes. And probably a ton of other things I'm missing.
Another option is alternate-day fasting. Eat normally for 3 days, then just don't eat anything for 24 hours. That's a built-in 3,000-5,000 calorie deficit a week, which will typically translate to a 1-2lb loss of weight. Well, probably more like 2-3 lbs because of all the water weight you'll drop along with body fat.
Don't put your trust in anyone on this forum, including me. You are the key to your own success.