The FastDay Forum

Do you need to burn more calories than what you eat to lose weight?

Or, you need to eat less than you burn in order to lose weight.

Or you can do a combination of both to loose weight...eat less and move more. In order to lose a pound a week (3500kcals) you need a daily deficit of around 500 from your overall energy expenditure. You can cut back your calories by 250 in addition to burning 250 calories to meet that goal.

However if you look at the way 5:2 functions that is easily achieved by slashing your intake on fasting days to 500 to give you ( depending on your level of TDEE, it is assumed that the average cal intake is 2000kcal/person) an approximate loss of .9-1 lb loss a week.

Personally given that my TDEE (totally daily expenditure) is somewhere around 1500-1550 I generally have to burn an additional 1500kcals during the week to attain a 1lbs loss.

In all it depends on your TDEE and of course your goal(s). Hope that clarified your question!

Cheers

Why do you ask grasshopper? Is there a deeper question? Sorry, I couldn't resist the Kung Fu reference. I sometimes think the calories in calories out is too simplistic but I don't have any scientific basis to refute it. I believe in the long run that it holds true, but in the short run I tend to hold on to weight then drop a couple. The same happens on gaining. For me, knowing this I factor it into my expectations so I don't get disillusioned. This WOE has been working for me.

Yes. Look at your TDEE. That is what your body needs to run on. Now deduct calories due to your fast days and voila you have a deficit. Your body burns calories constantly awake or asleep. I think whats really happening when you fast is that because your not taking in a lot of calories which is converted to glucose thru the digestion process. The body utilizes glucose for energy. If it does not have enough glucose to function your body will convert fat stores back into glucose as an energy source. So you see you will be burning fat.

Do you mean burn with exercise? No you don't
The biggest part of your calories burn goes toward keeping you alive and in good working order (BMR) + energy so you can live your life (NEET)+ exercise = TDEE. If you eat less than the somme of TDEE you lose weight.