Where does the fat go when you lose weight?

It is well known that obesity is one of the major public health concerns worldwide, many people are looking to lose fat. 

Though a lot of confusion still exists around the process of fat loss or fat burn.

Healthy Crumbs has come up with this article for a quick know how on what actually happens to fat when you lose weight.

How fat loss works

Excess consumed energy — usually calories from fats or carbs — is stored in fat cells in the form of triglycerides. This is how your body preserves energy for future needs. Over time, this excess energy results in a fat surplus that can affect your body shape and health.

To promote weight loss, you need to consume fewer calories than you burn. This is referred as a calorie deficit mode.

Though it varies from person to person, a daily 500-calorie deficit is a good position to start for a noticeable fat loss.

By maintaining a consistent calorie deficit, fats are released from fat cells and transported to the energy-producing machinery of the cells in your body called mitochondria. Here, the fat is broken down through a series of processes to produce energy.

If the calorie deficit continues, fat stores from your body will continue to be used as energy, resulting in reduction of body fat.

Over time, a consistent calorie deficit frees fat from fat cells, after which it is converted into energy to fuel up your body. As this process continues, the body fat stores are reduced and thus leading to changes in body composition.

Diet and exercise are key

The two main promoters of fat loss are diet and exercise.

A sufficient calorie deficit causes fats to be released from fat cells and used as energy.

Exercise amplifies this process by increasing blood flow to muscles and fat cells, releasing fats to be used for energy in muscle cells at a more rapid rate and this increases energy expenditure.

To promote weight loss, various studies recommends a minimum of 150–250 minutes of moderate-intensity exercise per week, equaling around 30–50 minutes of exercise for 5 days a week.

For maximum benefit, this exercise should be a combination of resistance training to maintain or increase muscle mass and aerobic exercise to increase calorie burn. 

Common resistance training exercises include lifting weights, bodyweight exercises, and resistance bands, while examples of aerobic exercise are running, biking, or using an elliptical machine.

When calorie restriction and a nutrient-dense diet are paired with a proper exercise regimen, fat loss is more likely to occur when compared to utilizing diet or exercise alone.

For best results, consider seeking help from a registered dietitian for dietary guidance and certified personal trainer for exercise programming.

Where does the fat go?

As the process of fat loss progresses, fat cells drastically shrink in size, resulting in visible changes in body composition.

Byproducts of fat loss

When body fat is broken down for energy through complex processes within your cells, two major byproducts are released — carbon dioxide and water.

The carbon dioxide is exhaled during breathing, and the water is disposed of through either urine, sweat, or exhaled air. Disposal of these byproducts is greatly elevated during exercise due to increased breathing and sweating.


Where do you lose fat first?

Commonly, people desire to lose weight from the belly, hips, thighs, and butt.

While spot reduction, or losing weight in a particular area, has not been shown to be effective, some people tend to lose weight from certain areas faster than others do.

Genetic and lifestyle factors play a significant role in body fat distribution.

Moreover, if you have a history of weight loss and weight regain, body fat may distribute differently due to changes in fat cells over time.

Why is it so hard to keep weight off for a longer time?

When you eat more than your body can burn, fat cells increase in both size and number.

When you lose fat, these same cells can shrink in size, though their number remains roughly the same. Thus, the primary reason for changes in body shape is a reduced size — not number — of fat cells.

This also means that when you lose weight, fat cells remain present, and if efforts are not made to maintain weight loss, they can easily grow in size again. Some studies suggest that this may be one reason why maintaining weight loss is so difficult for many people.