Dieting is indeed the most popular weight loss approach. But, many people tend to grow impatient with the “1-2 pounds per week” rule often recommended by health experts like myself. You’ve more than likely heard about this “safe” weight loss rate, but do you know why it’s so widely promoted? Truth is, people who achieve gradual, steady weight loss are more successful at keeping the weight off.
Believe it or not, weight regain is the most common side effect of losing more than 2 pounds a week.
So, why does this happen? Well, let me break it down for you.
Dieting essentially involves calorie restriction—That is, reducing food intake so as to consistently create calorie deficits that ultimately lead to weight loss. A pound of fat houses about 3,500 calories. So, if you create a 3,500-calorie deficit over a given period of time through dieting, you’ll eventually lose a pound of fat. Likewise, if you double that, creating a 7,000-calorie deficit, you’ll lose two pounds.
In and of itself, calorie restriction is perceived by your body as a threat—A lurking threat of ‘starvation’ to be exact. The less food you take in over an extended period of time, the more of a threat to your body.
The body generally adapts to reduced food intake by lowering your overall metabolic rate (metabolism). This is the rate at which your body burns calories to fuel (energize) vital functions. You can think of your metabolism as an engine fueled by the macronutrients (carbohydrates, fat and protein) housed in the foods you eat. When your metabolism is low, your body requires fewer calories to function.
However, a lower metabolism also means you’ll inherently burn less calories, which’ll compromise your ability to lose weight.
Calorie restriction is perceived by your body as a threat—A lurking threat of ‘starvation’ to be exact. The less food you take in over an extended period of time, the more of a threat to your body.
This is a primal, compensatory mechanism carried out by the body in an effort to prevent starvation and is very similar to the built in response of hibernating animals (also called the “starvation response”).
So, if you lose 15 pounds, for instance, in less than a month with low-calorie dieting, your body will start to adapt by lowering your metabolic rate to conserve energy. Over time, you’ll notice that you’re losing less and less weight, even if you’re still eating less.
But it doesn’t stop there!
Muscle wasting is another dreaded side effect.
This lean tissue is primarily comprised of protein. During the starvation response muscle proteins have a tendency to break down into amino acids (the building blocks of protein), which are then used to generate useable fuel. Simply put, amino acids will serve as a backup fuel source for your empty tank, but at the expense of your precious muscle tissue.
Since muscle is also very metabolically active, the less muscle you have, the lower your metabolic rate will be. Therefore, muscle wasting will further reduce your already reduced metabolism. And, once your normal eating patterns resume, your metabolism will remain sluggish. A sluggish metabolism favors excess fat storage and this is why you’ll ultimately regain any weight you’ve lost.
It’s all part of the protective mechanism.
Now, there is an exception: If you’re extremely overweight, you may initially experience rapid weight loss (4-5 pounds per week), as your body fat stores are generally functioning as “fuel reserves” and there’s a lot to spare. But, after about 4-6 weeks your weight loss will naturally taper off to the recommended rate.
The Net-Net: If you want to lose weight, err on the side of caution and shoot for a net weight loss of 1-2 pounds per week. Achieving this will require daily deficits of 500-1,000 calories, which averages to about 3,500-7,000 calories per week. To keep your metabolism in check, it’s best to incorporate regular exercise training into your weight loss plan. This’ll negate the need for extreme calorie restriction.
Instead of reducing your daily food intake by 1,000 calories in an attempt to lose 2 pounds per week, opt for 500-calorie reductions and then make an effort to burn an additional 500 with daily exercise. A combination of cardiovascular (cardio) exercise and resistance training is critical for preserving muscle tissue. Remember, increased muscle promotes a higher metabolism, meaning you’ll burn more calories and, ultimately, achieve greater weight loss over time.