Is a 1500 calorie deficit bad for really overweight people?

I keep reading in the forums that you should not have a greater than 1000 calorie deficit each day or else your body may go into "starvation mode" and it will hamper your weight loss. However, I have been achieving a 1500 calorie deficit per day on average and losing approximately 2-3 pounds a week. I keep my intake around 1500-1800 cals a day, and the larger deficit is mostly due to my workouts (cardio 5-6 days a week and weight training 2-3 days a week).

Is this bad for me? I'm 5'8", 234lbs, female, medium frame.

The problem with having that high of a deficit is your weekly weight loss isnt going to last. I am thinking it is going to halt altogether because your body is going to hold onto every calorie you give it because it needs it! If you dont give your body enough fuel you will eventually run out of gas and go nowhere. I would aim for no higher than 1000.

That hasn't been my experience. When I started out at 262 lbs (5'7"), I did a 1500 /day deficit.  I lost consistently all the way down to 172 pounds, where I was happy and went on to maintenance.  I never plateaued... not once.  I lost 12 pounds per month, every month, until I decided I was done.

That's just my experience. Yours may be different.

There is a limit to the amount of energy your body can get from a pound of fat each day (around 30 calories worth), if your deficit is so big that you can't get enough energy from your fat stores your body will burn muscle instead of fat.

If you have a lot of extra fat, you can eat at a higher deficit.

Original Post by kcnae3:

The problem with having that high of a deficit is your weekly weight loss isnt going to last. I am thinking it is going to halt altogether because your body is going to hold onto every calorie you give it because it needs it! If you dont give your body enough fuel you will eventually run out of gas and go nowhere. I would aim for no higher than 1000.

Yep, and if your body goes like that it will suck cus ull ruin ur metabolism and u will have to increase ur calories to normal calories or even a bit higher so your body gets used to using all the calories, you would start feeling tired all the time as wel... just dont go over 1000, i would say a 500 one would do =D!

if you are "losing" more than 1-2 pounds a week it's likely you aren't losing fat...when you don't give your body enough calories your body will start to eat away at muscle rather than fat.  muscle burns more calories than fat....so you then slow down your metabolism since your muscle mass decreases... all in all it's just a cascading effect.....

you probably also want to think in terms of lifestyle change/maintaining....rather than focusing specifically on losing weight think about what's healthy and what you will be able to do 10 years from now....it's more likely you'll take it off and keep it off....it can definitely be discouraging not getting there fast enough...but when you do it will be so much more worth it!

another tip to help increase your metabolism might be to give it a shock....maybe once a week boost your caloric intake 2400.....just to get your metabolism going....i'm 110 pounds and once a week i eat 2800 just to keep my metabolism up....i find that if i'm always eating low amounts of food everyday i actually start gaining weight!

A while back someone posted this site http://www.phord.com/cc/ 

It gives some good guidelines about how many calories to eat and how much deficit to have for YOUR body.  I think it said that you can safely loose 1% of your body weight a week.  Good Luck!!