Where does fat go when you lose it?

Most people know exactly where fat goes when they gain it. Some say their belly, some say their bum and some feel fuller in their face. But surprisingly, few people know where it goes when they lose it. Does it evaporate? Does it turn to muscle? Does it go when you, well … go?

The truth is, fat converts to carbon dioxide (CO2) and water. So essentially, you breathe, pee and sweat it out.

"Fat loss is the process of converting stored energy into other compounds that can be used elsewhere in the body. If they're not used, they're excreted," says Melissa Hughes, a registered dietitian and wellness program manager with
Sharp Rees-Stealy's Center for Health Management.

In childhood, your body is allocated a certain number of fat cells. That number generally stays the same throughout your life. When you eat, your digestive system breaks down food and stores it — making your fat cells expand. When you exercise — and your body needs that energy — the cells get smaller.

While there are exceptions — like some proteins that turn to liquid — 80 percent of the fat you burn turns into molecules that you breathe out. "Fat is broken down through lipolysis, which creates a molecule called adenosine triphosphate (ATP)," says Hughes. "As part of this process, CO2 is created as a waste product and exhaled."

So knowing this, why isn't breathing considered a form of exercise? Because exhalation and carbon dioxide production are not the same thing. No matter how much breathing you do, you can't make your body make more CO2.

What you can do is pay closer attention to the foods you eat, as well as exercise.

"The goal is always to get as much nutrition as possible from the foods that we eat, because it takes a lot of vitamins and minerals for the body to run efficiently and effectively," says Hughes. "This means focusing on whole-food proteins, carbohydrates and fats, and avoiding refined foods as much as possible.

To maintain a healthy weight or pursue a weight-loss goal, Hughes suggests the following five tips:

1. Minimize processed foods.
   Processed foods tend to be higher in unhealthy fats, sugar and sodium, while being lower in vitamins, minerals and fiber. Focusing on whole foods — fruits, vegetables, nuts, seeds, whole grains, legumes and lean proteins — maximizes nutrient intake for optimal health.

2. Eat at least five fruits and veggies a day.
   Fruits and vegetables are rich in nutrients, fiber and water, and they fill you up with fewer calories. Eat the rainbow! Eating fruits and vegetables in a variety of colors helps you get the vitamins and minerals you need every day.

3. Track all meals and snacks.
   Keeping a record of what you eat will help you stay accountable. A food log allows you to see what you're doing well and where you can improve.

4. Get at least 30 minutes of activity every day.
   Exercise can help you burn calories, maintain an elevated metabolism and improve your mood and sleep. Do it all at once or break it up into small bouts throughout the day.

5. Buddy up.
   Pursuing a health goal with a friend is fun, and having an accountability partner can provide support to help you stay on track.