I’ve been reading/hearing more and more about people wanting to lose weight by eating less. And when I mean less, I mean less than 1000 calories/day. Let’s examine this and if low-calorie intake is effective.
First, every person has a Basal Metabolic Rate (BMR) that tells you how many calories you need in a day for your body just to function. These calories go to your organs so they can do their daily tasks. I have never seen a BMR lower than 1000. In my profession, we do many health screenings and check people’s Body Mass Index (BMI) with instruments that can break down how much of your body is fat, water based weight, and bone mass; all components on your weight. The instruments will then calculate how many calories your body needs to do the essential tasks (BMR). Even in the heaviest person I ever encountered in these screenings, his BMR was 1500. Even with his weight, he still needed 1500 calories per day just so his brain, liver, heart, kidneys, GI tract, etc. could do their jobs.
The question then arises, “If I take in less than my BMR, my body will have to use it’s stored energy to make up the difference, right?” Yes and no. Your body will use it’s stored energy, but when you take in less than what your BMR calls for, you are in a fasting state. (Read my post about what happens to your body when you exercise in a fasting state: Exercise Before Breakfast: Beneficial?) Your body doesn’t just use fat as energy. It uses sugars (glucose/glycogen) and proteins (amino acids) stored elsewhere in your body, specifically your muscles. Big deal… Well it is, since your muscles are the best at burning fat. Most organs cannot use fat as energy until it’s broken down into another form, which takes longer to produce it into useful energy. But the glycogen and amino acids are used fairly quickly, so they will get used first.
Ok enough with the science, what does this all mean? When you eat less that what your BMR calls for, your body will eat away at the things it needs most to lose the fat (adipose tissue). You will see results on the scale, but then when you get down to that target weight, and start eating more calories again, you’ll gain it right back. Sounds like yo-yo effect to me.
There is a solution!! Eating the correct amount of calories, from healthy, nutrient rich sources, for your goals (because you may have to eat MORE to reach your goals) and burning them off through exercise. Only then will your muscles adapt, and continue to burn fat efficiently so you can see the results you want, fat loss. No magic pill, diet drink, or magic potion from the 1950s will do it. You must eat healthier and do the work.
- BMR Calculator (billycorbett.wordpress.com)
- What Are Calories? (superabs.wordpress.com)
- What’s BMR and Why it Matters (fitusculpt.wordpress.com)
- 10 iPhone Apps For Counting Calories (iphone.appstorm.net)
April 13, 2011 | Categories: Drinking, Eating, Fitness, Nutrition, supplement | Tags: Basal Metabolic Rate, Body mass index, Caloric Intake, Calorie, Diet food, Eating, Exercise, Fat, Fitness, Food, Health, Muscle, Nutrition, Physical exercise, Weight Loss, Workout | 1 Comment