How much calorie deficit is too much?

Yes a net of 800 is far too low. Eat those calories back or figure your TDEE and set your calories at TDEE -20%

Yes a net of 800 is far too low. Eat those calories back or figure your TDEE and set your calories at TDEE -20%

^

By eating a small amount of calories does not mean you will lose weight. Even 1200 is too low. I would raise it to 1600 (still quite low) and then add your exercise calories on top and make sure you eat them all. If you keep your calories low, your body will go in shock and store fat.
Try it and you will see how better you feel and the weight will shift a lot quicker
Good luck

General guideline is TDEE minus 20% maximum.

Side effects of an extremely low net calorie diet include fatigue, lowered immune system, bone density loss, impaired motor functions, slower reaction times, hormone imbalance, slower metabolism, organ damage (skin is an organ), may cause type 2 diabetes, muscle loss (your heart is a muscle), hair loses it's sheen and thins out, etc.

So yes, you will be losing weight while on this type of diet, but it's coming from your bones and your muscles and your organs. Congratulations! You weigh less.

http://www.livestrong.com/article/498761-side-effects-of-too-much-exercise-not-enough-calories/
http://www.livestrong.com/article/325139-side-effects-of-not-enough-calories/
http://www.coachcalorie.com/not-eating-enough-calories-to-lose-weight/

* Note, if your BMI is over 30 you can get away with extremely low calorie for a short time, but you should only do so under a doctor's supervision as there are extreme health risks.

TDEE is Total Daily Energy Expenditure. Resting Metabolic Rate + Lifestyle Calories + Exercise Calories.

Dear all. Please help us. I have the same problem. I weigh 51 kg for 152 cm 25 years old, female.
Lost around 27 kg over 1 year.
I exercise a lot these days. Burning between 200 and 400 cals.
BUT I have been eating 880 -990 cals per day even on exercise day. Is this enough ? I truly don't think so.

I try to increase but I fear too much fat or carbs then weight gain.

Any advice will help !
Million thanks in advance.

that depends on how lean you are already:

people who are very obese according to body fat percentage: TDEE -30% is a good deficit as when you have a lot of fat to lose, you can lose it more easily with less risk of losing lean tissue in the process. However it's still a good idea to do weight bearing exercise in order to prevent loss of lean tissue

People who are already lean, i.e. body fat percentage is already in the healthy range, who are looking to lose more body fat for cosmetic reasons: TDEE - 15%, or even TDEE - 10% is safer. This means a slower rate of fat loss, but there's also a much greater risk of losing lean body mass if the deficit is too big. It would also be necessary to do weight training or other exercises (e.g. bodyweight equivalents to weight training) that work the muscles hard in order to maintain lean tissue.

People who are in between, i.e. body fat percentage is above the healthy range but they're not very obese, TDEE -20% is best. That's probably most people. (and a good exercise programme is still important for preventing lean tissue losses) Just that if you fall into either of the above categories, 20% may not be optimal for you. TDEE -20% won't do any harm to the very obese, they will still lose fat, it might just take a bit longer. However TDEE -20% could very well be too big a deficit for the already lean. The leaner you are, the harder it is to lose fat and the more risk there is of losing lean tissue along with any fat losses, hence the need to have a smaller deficit.

Im in the same confusion boat.

Started off on the 1200 cals per day and lost around 15 pounds and have plateaued since October. If my TDEE is 2259 and I minus 20% does that mean I should be eating around 1807 cals a day?

stats: 31 yrs old, Female, weigh 67kgs, height 5'5 and workout 3 - 5 times per week.
Let me know if I worked out the TDEE incorrectly. I used: http://www.fitnessfrog.com/calculators/tdee-calculator.html


BMR: 1450

You could do it that way, eat around 1600-1700 a day or you could keep calories at 1200 and have one spike day a week at 2800-3000. Your choice.

Thank you for your advice. I am going to keep trying. I used to be even lower than that. i'll try harder. What do you think? next cap in the 1000 cals maintain that for two weeks or more then 1200 cals. It should be safe right and I will not risk weight gain I hope.

Again many thanks

Yes, that sounds great. Your weight might swing up a bit for a short period but it should straighten itself back out.

Dear all. Please help us. I have the same problem. I weigh 51 kg for 152 cm 25 years old, female.
Lost around 27 kg over 1 year.
I exercise a lot these days. Burning between 200 and 400 cals.
BUT I have been eating 880 -990 cals per day even on exercise day. Is this enough ? I truly don't think so.

I try to increase but I fear too much fat or carbs then weight gain.

Any advice will help !
Million thanks in advance.

Yes..........please increase calories. Do it slowly and the scale shouldn't change much. You should probably be around 1300-1500 to maintain and be healthy.

Thank you for your advice. I am going to keep trying. I used to be even lower than that. i'll try harder. What do you think? next cap in the 1000 cals maintain that for two weeks or more then 1200 cals. It should be safe right and I will not risk weight gain I hope.

Again many thanks

That should work perfect and you are welcome.