Give Now

A Moment of Science

Why Does Weight Loss Slow Down After A While?

Losing weight can be a frustrating experience when you hit a point where the weight slowly comes off. Learn why the process slow down.

weight loss tape

Photo: Darren Hester (flickr)

Getting rid of the inches can be tough!

Losing weight can be frustrating, especially as the initial relatively quick–weight-loss of the first few days tapers off.

But if your aim is to get rid of fat, those first few days aren’t really accomplishing anything. Only when your weight loss slows down is your body beginning to get rid of fat.

What Is Fat?

Fat is one way your body stores excess calories that you consume but don’t use. Fat is an efficient way of storing energy because it contains more calories per gram than other forms of food. By dieting and exercising, you force your body to use up its reserve stores of fat to get the calories it needs.

But our bodies also store excess food in the form of a complex sugar called “glycogen,” which can be used more quickly than fat but is much heavier. In addition, glycogen has to be stored with water, which weighs about three times as much as the glycogen itself.

At The Start Of A Diet…

When you first start dieting, your body uses up the most available source of energy–the glycogen. As it does so, the water stored with the glycogen is released and you can lose over a pound a day, but most of that weight is water.

When your body’s supply of glycogen gets low, it turns to the fat. But since the energy in fat is more concentrated and the fat doesn’t contain water, even the strictest diet won’t take off more than about a half pound per day.

Slow, Steady Weight Loss

Once your body begins using fat, it also replenishes some of its supply of glycogen. Since a small amount of fat holds the same number of calories as a large amount of glycogen, some people even gain weight at this stage of a diet.

Eventually, your body’s store of glycogen evens out. At that point, dieting can produce a slow, steady weight loss.

Stay Connected

What is RSS? RSS makes it possible to subscribe to a website's updates instead of visiting it by delivering new posts to your RSS reader automatically. Choose to receive some or all of the updates from A Moment of Science:

Support for Indiana Public Media Comes From

About A Moment of Science

Search A Moment of Science