maintenance calories calculator?

JeremiahStone

whats the best way to calculate the lowest amount of calories you could be on without harming your body?

yarwell

whats the best way to calculate the lowest amount of calories you could be on without harming your body?

Use a nutritional software package or web site to formulate a diet that provides everything you need, then see how many calories that comes with. I managed it at 1150 once, though could do better if I tried again. A couple of supplements would have put a hole in it.

Looking at it another way, there are nutritionally complete diet formulations around the 500 calorie mark, sold commercially and recommended for medical use with obese patients. Optifast is one brand.

RuthieCass

I'm not really clear on what you mean exactly by not "harming your body." If it's vitamin deficiencies you're concerned about, you can use supplements as yarwell suggested. If you do want to do a very low calorie diet (500-800 calories), I would suggest that you see a doctor AND nutritionist about coming up with a plan, though. On such diets, you need to be very very strict about adhering to the prescribed diets.

If you're concerned with harming your body in terms of a metabolic slowdown: all diets will do this to some extent since lower weight means lower TDEE. There's a lot of alarmist talk about "starvation mode" on these boards, but your body will probably slow down more in the face of a very large deficit than it would in the face of a small deficit. If you are obese and sedentary, though, this may not be that much of an issue for you. And the "slow down" will probably be less than the decrease in calories. E.g., if you are comparing a 500 calorie diet to a 1500 calorie diet, you will eventually lose more weight on the 500 diet, even if your metabolism slows down more. A lot of this slow down is temporary, but it will take some time for your body to adjust back to "normal" calories.

If you're concerned with minimizing muscle loss, you will need to consume more than a VLCD. I've seen recommendations that you should eat 1-1.5 g of protein per lb of LBM or goal weight when eating at a deficit to avoid muscle loss. Fat: 0.3-0.6 g per lb of goal weight. Carbs are a little more tricky since there is apparently no technical physiological necessity for carbs and is more dependent on level of activity & cardio and tolerance for ketosis. A practical minimum is 50 g of carbs; 100 g of carbs if you want to avoid ketosis. So suppose your goal body weight is 175 and LBM is 150. Using the 1 g protein=4 cals, 1 g fat=9 cals, 1 g carb= 4 cals, and taking the minimums of the above ranges, you would get:

total minimum calories = protein calories + fat calories + carb calories
total minimum calories = 150X1X4 + 175X0.3X9 + 50X4 = 1273
*or 1473 to avoid ketosis

Of course, the biggest problem with cutting calories so low is long-term adherence. Most people don't do so great on a 1200 calorie diet, much less a VLCD. It's better to pick a plan you can stick to for a long time than it is to do crash diets where you cut your calories too low and then end up bingeing.