Hi, so I heard doctor fung talk about how fasting for periods of 3-4 days won’t slow your metabolism. He showed a chart of someone’s metabolism when on a traditional low calorie diet wich included carbs compared to someone fasting. The person on the fasting diet maintained there metabolic output and the person on the low calrie normal carb diet slowed. My question is if I were to follow a low carb or keto diet if my metabolism would slow due to caloric restriction. I would much rather restrict calories and carbs then go 3-4 days without eating
If you don’t do IF, I don’t recommend jumping straight into multi-day fasts. It’ll be excessively difficult and if you are already on the fence about it, you’ll probably give it up.
What I do recommend is starting off with a keto diet and slowly work your way into longer IF fasts. Once you have an easy time with longer fasts, whether 20:4 or OMAD, THEN consider multi-day fasts. It is easier going into them when you are on a keto diet because you are fat adapted, but make sure to keep up with your electrolytes if you are prone to keto flu symptoms. I don’t really need much electrolyte supplementation anymore, but the first one made me feel terrible until I upped my salts.
Everything I have seen from Fung suggests that calorie reduction as primary regardless of the type of diet eventually leads to reduction in daily calorie expenditure by the body. As your calories per day go down. He body adjust and burns less calories too. But considering low carb has less insulin response by the body. There might be a chance that that your body is less likely to store incoming excess calories like it would on a high carb SAD.