Tuesday, August 10, 2010

How to Effectively Create a Calorie Deficit.

In order to lose weight you have to have a calorie deficit, no if, ands, or buts about it. Like I said before it's all energy balance and our body gets energy in three main ways:

  1. Calories from the foods we eat
  2. Stored glycogen in our liver and muscles
  3. body-fat
Our body prefers glycogen while we exercise and a mix of the food we eat and body-fat at other times.  While we rest our body uses the highest percentage of body-fat when we have a calorie deficit. 

This post is about being effective, and I think effective means long term results.  Yes, if you only ate 800 calories and exercised for several hours a day you would lose a lot of weight in the short-term, but it would haunt you in the end when your metabolism shuts down on you. It is best to do it gradually.

The math is very simple, 3,500 calories is equal to one pound of body-fat. So if you want to lose one pound a week you need a daily deficit average of 500, and for two pounds an average deficit of 1,000.

You can get this deficit by simply eating less or just by increasing exercise. The fact is our body just sees the net of our calories in versus our calories out so you can do it anyway you like, but yet again effective long-term results come from a combination of diet and exercise. 

If your goal is to lose two pounds a week, then daily in some sort of combination of diet and exercise you need to have a net of -1,000 calories. 

This again is why it is so important to log your calories.  If you simply guess how much you ate, you are setting yourself up for heartbreak and failure. 


  1. So you would take your BMR and subtract 500-1000 from that?

  2. Hey Abby, I'm sorry I thought I replied to you about this yesterday.

    Yeah that would work, but you do not want to go below 1,200 calories eaten. When we eat fewer than that we usually miss out on a few essential nutrients. The idea is to have about a 1,000 calorie deficit from your BMR + your exercise and activities. So if your BMR is 1,600 and you burned an extra 800 calories with actives and workouts, your "calories out" would be at 2,400, so then you would eat 1,400 causing a 1,000 calorie deficit. The idea is your body will be forced to burn bodyfat to make up that 1,000 calories and once you reach 3,500 calories burned you have lost a pound of fat.

    If your goal is 2lbs a week, that would be 25 pounds in 3 months.