It seems that long term fasting, in theory, would be the most effective way to lose bodyfat. I keep my blood sugar stable, insulin low, eat keto, and supplement electrolytes. I’m typically on a 20/4 fasting schedule. During those 4 hours and beyond, am I not using that dietary fat (instead of bodyfat) for fuel? If so, I should eat as few fat/protein calories as possible during this time ?(restrict calories). Note that at 5’10” 255lbs, I’d like to lose at least 40 more pounds (SW 286). I’ve seen some recommendations of no more than one 72 hour fast every few months. For bodyfat reduction, it seems the more long term fasts you can withstand the better, especially with high bodyfat levels like mine. So calories count or no?
I think there is a misconception that Dr Fung does not think calories matter, energy consumption still matters. His point is eating 1500 calories of protein, fat and veggies in 4 hours is significantly different than eating processed sugars throughout the day, even if you still only eat 1500 calories. 20/4 throw in some alternate days and stay below your tdee in your window while eating clean and you have no choice but to lose weight.
Correct, when eating and for some hours after, you are not burning your body fat. And when you do go longer, if you are in keto, and burning fat, yet eating too much fat, you will burn what you eat, not your body fat.
https://idmprogram.com/fasting-physiology-part-ii/
Consider longer fasts and more often.
I mean, if you want to do a calorie restriction fast, you can consume < 500 calories during your feeding window.
For keto, that will be MOSTLY fat - which is why something like a bulletproof coffee can work.
This is because, at that point, you are hopefully fat adapted and can use those fats for energy.
Too much protein can cause issues because it can be more readily converted to glucose.
> Note that at 5’10” 255lbs, I’d like to lose at least 40 more pounds (SW 286).
You’re currently at BMI 36.6, so this is a reasonable desire.
> I’ve seen some recommendations of no more than one 72 hour fast every few months.
If you follow Dr. Fung’s safer-fasting recommendations, you can fast far more often than this. If you read my safer-fasting guide, you can learn more about Dr. Fung’s advice.
Megan Ramos would say: ‘Eat whole, unprocessed food and fats until sated.’ Satiety is key to feasting when fasting. Not eating beyond hunger and not going into leptin resistance. Listen to your body tell you you’re sated because really, calories usually cannot be counted accurately.