I am a fairly large man at 6'5" - 6'6" and have seen my weight go from 225 lbs to 320 lbs at various points between body building, working out and at one point just getting fat. In my experience a combo of limiting carbohydrates and calorie intake made the biggest difference, coupled with fasting. I lost 60 lbs in 60 days by eating one meal a day and skipping eating for a day once a week. It was hard the first 48 hours but then got easier... so far I have kept a 34 inch waist at 260 lbs and lifting 3-4 times a week. Having said that, potatoes as a diet sounds like a poor choice.
I think a good strategy is to increase protein intake and try to exercise as hard as you can for a month or so and then slowly cut back on carbs (potatoes) and replace with healthier options. For me, after starting protein shakes and working out pretty intensively 4-5 days a week early this year I crave healthier foods and will choose them over junk food if available and I’m properly hydrated. My cravings for alcohol have basically stopped which for me was huge in terms of carbs. Not very original advice but it’s taken me a long time to get back to basics and lose the belly fat. A potato only diet will keep you craving carbs which are fine in moderation if you’re pushing yourself along with a lot of protein.
I've tried all these fad diets and all of them worked until they didn't. None of them are sustainable. The only thing that's worked for me is just eating healthier options. Grilled chicken sandwich instead of bacon cheeseburger. Vegetables instead of cheese fries. Tea or water instead of soda. Light beer instead of margarita. Salsa and pico instead of sour cream and queso. 80 oz of water every day. I lost 40 pounds a few years ago and I've been able to keep it off since then by just eating a sensible diet, drinking lots of water and exercising for an hour a day. People tend to overthink all of this when it's really pretty simple. Moderation
Not really a diet per se, but as far as recalibrating your habits (which often times will result in weight loss anyway), Whole30 has worked wonders for me. I've done it four times, basically whenever I feel I am reverting to bad eating habits again. In short, for 30 consecutive days you limit your intake to just fruits, vegetables, and lean meats. All sugar, grains, soy, and dairy are eliminated, as well as sodas (even diet drinks) and alcohol, but up to two glasses of dry wine is permitted per day. Not permanently sustainable, but by the time you're done you will find yourself avoiding the prohibited foods naturally. This got me off of diet soda and beer for about a year. And other little things here and there have stayed with me, like when I order salads at lunch I hold the cheese and dressing, opt for oil and vinegar. On top of the resulting weight loss, I found myself having more energy during the day, more effective workouts, and waaaaaay better sleep at night.
