Skip Nav

How Does Fat Leave the Body?

Once and For All, This Is What Happens to Your Fat When You Lose Weight

When we make lifestyle adjustments that involve healthier eating and regular workouts, we typically shed a few pounds and see a decrease in body fat. It's not that we miss it or anything, but it's not unusual to wonder where body fat goes to die (so to speak). I mean, it has to go somewhere, right? Personally, this question had me completely befuddled so I talked to two experts about exactly how fat leaves the body.

"Adipose tissue, or what we call the fat layer, is made of adipocytes, [which are] the cells that accumulate fat droplets for the purpose of energy storage, as well as to insulate the body," Dr. Luiza Petre, a board-certified cardiologist, told POPSUGAR. Every person has a genetic predisposition for the number of fat cells they're born with, and this number tends to remain steady throughout their life. So when we lose weight and body fat, we're not actually losing these fat cells.

"When you begin to lose weight, your fat cells decrease in size. In other words, they shrink but they are still there," Dr. Petre explained. "They don't go anywhere; they kind of just lose weight like you do." But unless they're mechanically destroyed or surgically removed, the number of fat cells stays the same.

Every person needs body fat to survive, so fat cells serve a crucial purpose to our health and well-being. "Fat cells are energy storage cells," Dr. Susan Besser of Mercy Medical centre, told POPSUGAR. "They collect and store energy in the shape of fat and hold it until the body needs the energy released."

Dr. Besser explained that individual fat cells become more "plump" when the body has a higher amount of stored energy. When we lose weight, our bodies use the stored fat in these cells for energy because "the external sources of energy (food) become less available." As the body uses the stored fat for energy, the fat cells shrink. "[It's] sort of like a balloon shrinks as the air leaks out of it," Besser said. "The fat cells are still there, just smaller."

Because we don't actually lose fat cells when we slim down and lower our body fat percentage, the cells always have the potential to return to their previous size or larger. "The potential for replumping those cells is still there, so with increasing energy storage the fat comes back," Dr. Besser said.

Again, the only exception is to surgically remove fat cells through procedures like liposuction — and who wants to have a potentially dangerous surgery when there are plenty of fun workouts and delicious healthy food options out there?

Latest Health & Fitness