How many calories is too few?

I’m in a pretty rigorous fitness and nutrition schedule. I lift weights, run, and do yoga, and I try and keep my caloric and fat intake to a minimum. My body fat is around 12% and I’d like to get to 10% or even 8%. Today I approximate I burnt about 500 or 600 calories at the gym, and I ate around 700, a good portion of which was lean protein.

I’m told 2000 calories a day is right for my age and activity level. My first question is; are those net calories (after the result of exercise is deducted) or gross caloric intake? Secondly, what if any are the disadvantages of going well under 2000 a day?

height, weight, frame size and gender, please?

Woah… wanna buy me a drink first? :wink:

5’9", 165 lbs, lean/athletic, male

The 2000 calorie total should be your daily intake of calories. With exercise you should eat more. To lose wait, you can cut calories and exercise, but not to the extent that you are. 700 calories a day for someone your size, with exercise is a quick way to end up exhausted, injured, or dead. BTW…why, at 12% body fat, are you dieting? If I were you, trying to get that little extra ‘lean edge,’ I’d keep my caloric intake pretty steady, at around 2,000, and just increase the exercise…or decrease the calories you usually eat by a small amount, perhaps 100-200 a day at most. It will take longer to come off, but it will be much healthier and will stay off.

If you want to lower your body fat, you don’t want to go below 2000 calories a day. Even then, you may need more.

Weight loss, unusually excessive body odor, excessive gas, general fatigue, constipation – I’ve been running 1400-1600 calories a day for a while, and have exhibited all of these symptoms at various times.

Being hungry all the time and not enjoying food and drink the way a person should.

That’s a massive caloric deficit. I mean, you’re burning 600 at the gym. You’re burning many more just in your daily activities.

Not that it’s material to your questions, but why do you want to get such low bady fat %?

It really depends on your goal. If your goal is to look ripped with a decent amount of muscle, you’re not eating nearly enough. But if you’re realy interested in just eating less for health reason, check out the information on Calorie Restriction. Years of research indicate that keeping your caloric intake down can improve health and extend life. The downsides can be things like feelings of hunger, appearing too thin, increased cold intolerance, etc. Plus, it seems that eating too little can sometimes lead to an unhealthy preoccupation with weight loss and food.

Well I’m trying to get below 10% for purely aesthetic reasons (read: vanity). Also, the exercise and dieting do make me feel better physically and emotionally. But a few follow up questions:

Can I take an average caloric intake for the week? Say I tailgate at the game and eat 2000 calories just at the bbq (not an unlikely possibility) and then eat 700 – 1500 a day the rest of the week; is my body getting what it needs then, or are the daily units discrete?

Failing that… what exactly is a good nutrition plan for someone in my position? Is 2000 a day minimum is really necessary to lose fat and maintain/build muscle?

Here is a better calculator for your BMR (that 2000 calorie number). The real number is probably lower in your case.

If you’re trying to drop below 10% bodyfat, calculating your caloric needs by the day is probably not accurate enough. Go read this and you’ll find lots of info.