Metabolism and bmr question?

[Anonymous]

Hypothetically, if someone ate 400-800kcal every day and lost weight now isn’t losing weight. Is it possible that their bmr has lowered to 800 and they’d have to eat less than that to carry on?
Thank you for your response and time I appreciate you!

[BagoH]

You need to look at it as a whole. BMR is not your total calorie expenditure. TDEE is, that is your total daily energy expenditure under which bmr also falls.

After a certain period of caloric deficit your body loses weight and adjusts to your current caloric intake. Fewer weight to carry = fewer calories required and thus fat loss slows down / stops unless you keep lowering your calories.

[BagoH]

With that being said , you only need maximum 500 calories less than you need to maintain your weight for a healthy fat loss. Also keep proteins at 1g per lbs in bodyweight to make sure to prevent muscle loss while losing fat.

[Asker]

Thank you for this response!! So can the tdee become 800 if that person was to eat 800? And is it possible to damage your tdee?

[BagoH]

TDEE is expenditure (calories out )
800 calories (calories in) are two independent factors. You can eat 800 cals a day but use 1200 for example. Under TDEE falls bmr, tef, neat , calories consumed. And when you add exercise to it all you use even more calories.

[BagoH]

Your TDEE changes based on your physical activity, calorie consumption , neat , tef.

[Asker]

Oh okay thank you sm

[BagoH]

you're welcome !

[WindAtMyBack]

That's almost a starvation diet. I don't know how BMR is calculated, but if it gets low enough, sure, you will need to eat few calories to lose weight.

But if you can't lose weight at 400-800 calories a day, then you should quit trying to lose weight and stop starving yourself. You could be doing serious damage to yourself.

[WindAtMyBack]

*fewer calories

[pascal_climbs]

Even 800 kcal is too low. Your body goes into starvation mode to protect itself. A normal light person has a BMR between 1500 and 2000 kcal. But that you have to multiply by your activity level. A good healthy food pattern is appr 400 kcal below that number. Even babies burn more than 800 kcal.

[WanderingLoveWizard]

I don't know what any of that means. And you're welcome

[Asker]

Hahah have a nice day☺️