Exercise stimulates muscular growth (or cardio endurance, depending), but it’s woefully inefficient at burning fat. The number of calories you burn in even lengthy and grueling cardio is miniscule compared to the number of calories you put in your mouth in just a couple minutes. There is no way to eat whatever you want and just exercise harder to make up for it. It doesn’t work. Calorie restriction is the only path to fat loss.
I’m a big fan of water fasting, partly because of the added physiological benefits, and partly because of the mental/spiritual discipline it builds. I do it regularly. I’ve done up to 4 days. Read Jason Fung on the medical side.
But of course a water fast isn’t indefinitely sustainable.
The most effective sustainable approach I’ve personally done is a combination of keto with OMAD (one meal a day). Actually it wasn’t keto because I allowed carbs like baked potato – but it was grain free and sugar free.
You get a one hour eating window each day (say whenever your family eats supper), and during that hour you eat as much as you want, but no grains (bread, pasta) and no sugar.
I lose weight quickly on that.
And if you think it’s not sustainable … honestly it is.
Ramp up to it by spending one week eating whenever you want, but no grains and no sugar. Adjust to those restrictions.
Then in the second week, still sticking to those restrictions, start backing up meal times by 2 hrs. each day – 9am, 11am, 1pm, 3 pm, until finally you’re eating only supper.
By the time you get to only supper, it won’t seem as bad as you think it will. And after a few days on the full regimen, you’ll feel completely used to it.