Despite promises made by some popular workout techniques, fitness influencers and magazines, spot reduction — the idea that you can target weight loss in a specific area of your body, such as the belly or thighs, via certain foods or exercises — isn't a real thing.
"The scientific consensus among fitness experts and researchers is that spot reduction is a myth," Tony Carvajal, a certified L-2 CrossFit Trainer with RSP Nutrition, tells LIVESTRONG.com.
Here, Carvajal and other experts explain how weight loss actually works and the best course of action if you really want to trim your waistline or slim your thighs.
How Weight Loss Really Works
To understand the process of losing weight, weight loss specialist and board-certified cardiologist Luiza Petre, MD, suggests thinking of your body as a furnace that needs fuel (energy) to burn (perform its functions). "Fuel comes from what we ingest as food or from stored energy in the form of fat," she explains. When we ingest excess energy, our bodies store it as fat, and we gain weight. When we burn more than we ingest, though, our bodies draw from that fat store, and we lose weight.
Basically, successful weight loss comes down to eating fewer calories and exercising to burn more energy. "If you cut just 200 calories a day from your diet and burned just 300 extra calories a day by exercising, you'd lose about one pound per week," explains Carvajal.
That's because a pound of fat is equal to about 3,500 calories, according to the Mayo Clinic. So by creating a 500-calorie deficit each day, you'll be down 3,500 calories (or 1 pound) by the end of the week. The Mayo Clinic recommends cutting no more than 1,000 calories per day, for a maximum loss of 2 pounds per week. Any more than that may not be safe or sustainable.
Why Spot Reduction Isn't Possible
While doing set after set of crunches, sit-ups or other popular abdominal exercises will definitely strengthen and tighten stomach muscles, it's not necessarily going to blast the fat in that specific area.
Carolyn Dean, MD, ND, bestselling author and founder of RnA ReSet, offers a simple explanation as to why spot reduction simply isn't feasible: "The body's metabolism occurs body-wide — it doesn't focus on any one area."
A more in-depth explanation has to do with the number of fat cells, or adipocytes, in our body, explains Dr. Petre. These fat cells can increase in number during periods of hormonal changes, such as puberty and pregnancy, but their number otherwise tends to stay consistent throughout our lives. What can change, though, is the cells' size.
"Compare them with bubbles that can go bigger or smaller as they need to store more or less fat," Dr. Petre suggests. Gaining or losing weight is like inflating or deflating the "bubbles," she says, but either way, it's happening to all of the "bubbles" at the same time.
However, Dr. Petre explains, so many people think spot treatment is valid because it can often seem like we are losing more weight in a certain area of our body — when it actually means that our bodies simply have more or less fat cells in certain areas.
"An individual carrying more fat around the waist than in the arms and legs, for example, may notice a more significant decrease in fat around the belly, where body fat percentage is higher," explains Geoffrey Nadzam, MD, a bariatric surgeon at Yale Medicine.
Read more: How to Estimate Your Body Fat Percentage
Some People Hold Weight in Different Parts of the Body
There are a number of reasons why each of us tends to hold fat in different areas of our body, and most have to do with our genes. "Areas of fat cell concentration are determined by sex and genetics," says Dr. Petre. Men usually have more around the abdomen area and women in their hips and thighs. "So when the 'bubbles' increase in size, it looks more obvious in those areas where the cells are more concentrated," she explains.
Other lifestyle factors, such as stress and diet, can also affect where you store fat. "Stress cortisol will store belly fat," says Dr. Dean. In other words, the hormone cortisol, which is released when you're under stress, signals your body to store fat in your midsection.
Read more: 10 Foods to Avoid for a Flat Belly
So, What Should You Focus on When It Comes to Weight Loss?
According to multiple studies, high-intensity interval training (HIIT) is among the most effective ways to burn calories and fat. For example, a January 2017 Journal of Diabetes Research study found that HIIT was a much more effective weight-loss tool than steady-state cardio.
Even more important than what workout you do, though, is simply being consistent with exercise. The most effective regimen is the one you enjoy and ultimately stick with in the long run.
And to really lose weight and burn fat, maintaining a healthy diet is absolutely crucial. Experts are generally torn as to which diet is the most effective for weight loss — hence all of the trendy fad diets out there, from keto to intermittent fasting. Overall, there doesn't seem to be a one-size-fits-all solution because each person is unique. But for healthy and sustainable weight loss, the Mayo Clinic suggests looking for a diet that is balanced and flexible, includes food you like and encourages exercise.
The bottom line? "The solution to fat loss is healthy calorie intake, increased exercise and consistency," says Carvajal.