The Flat Belly Diet
The Flat Belly Diet promises readers that they can trim their waistline and lose belly fat, all without a single crunch. Find out if the flat belly diet really delivers.
By Katherine Lee | Medically reviewed by Pat F. Bass III, MD, MPH
The Flat Belly Diet by Prevention Magazine editor-in-chief Liz Vaccariello and Cynthia Sass, RD, promises readers the tools they need to lose belly fat for good without doing a single crunch and while dropping up to 15 pounds in 32 days.
The basic foundation of the Flat Belly Diet is evidence the authors say links monounsaturated fatty acids (MUFAs) to a reduction in belly fat. By eating MUFAs at every meal, the Flat Belly Diet claims it can flatten your stomach and help you lose belly fat permanently.
The Flat Belly Diet: How Does It Work?
There are two parts to the Flat Belly Diet: a four-day jump-start period that is supposed to flush out the system, followed by a four-week eating plan. The jump-start phase allows only 1,200 calories a day; the four-week phase increases calorie intake to 1,600. Each phase is broken up into three meals and a snack, and shopping lists and sample menus are provided.
During the jump-start phase, readers are instructed to avoid salt, processed foods, high-carb foods such as pasta and bagels, and gas-producing foods such as cabbage, onions, and legumes. Followers of the Flat Belly Diet are also told to avoid coffee, tea, sugar alcohols, and carbonated drinks, and instead drink two liters of “sassy water” (a mix of ginger root, cucumber, lemon, and mint leaves) every day.
During the four-week period of the flat belly diet, each meal must have a MUFA and dieters are told never to go more than four hours without eating.
The Flat Belly Diet: Sample Diet Day
1 flax-enriched waffle topped with 1/2 cup sliced banana, 2 tablespoons pecans, cinnamon, and nutmeg
1/2 cup each burger meat and baby spinach leaves, 1/4 cup sliced avocado, and salsa divided evenly among four small corn tortillas
3 ounces grilled wild salmon and 1.5 cups green beans tossed with 2 tablespoons sliced almonds
1 packet instant hot oatmeal with 1 cup blueberries and 2 tablespoons almonds
The Flat Belly Diet: Pros
The biggest advantage to the Flat Belly Diet is the healthful food choices included in the meal plans. “The flat belly diet says to eat avocados, olive oil, nuts, seeds, and fish and to avoid meat and saturated fat, very much like a Mediterranean diet,” says Lona Sandon, RD, American Dietetic Association spokesperson. “It says to eat monounsaturated fats, which are healthy for the heart.”
Other health benefits have been linked to a Mediterranean-style diet. “There is some evidence that the Mediterranean diet can help lower your risk of cardiovascular disease, cancer, and Alzheimer’s disease,” says Amy Jamieson-Petonic, RD, a wellness manager at Cleveland Clinic and also a spokesperson for the American Dietetic Association.
The Flat Belly Diet also includes meal-replacement options and good choices for eating out at fast-food restaurants, which is helpful for today’s busy dieters.
The Flat Belly Diet: Cons
One major problem with this diet is that it oversells the concept that MUFAs magically help you lose belly fat, says Sandon. And while there is a chapter on the benefits of exercise, the Flat Belly Diet only emphasizes eating MUFAs to lose weight and claims that not a single crunch is required. “There is nothing on stress management or lifestyle,” says Jamieson-Petonic. “Monounsaturated fat is not a silver bullet for weight loss.”
Another drawback to the flat belly diet is the lack of research to support recommendations such as drinking the sassy water. “There is no scientific evidence that ‘sassy water’ will jump-start your metabolism,” says Jamieson-Petonic. And the recommendation to suddenly stop drinking caffeine fails to take into account that doing so could lead to withdrawal symptoms such as headaches.
Finally, the Flat Belly Diet fails to adjust calories for variable factors such as height, weight, and activity level. “For some people, 1,600 calories may not be enough,” says Jamieson-Petonic. “If you’re a runner, for instance, you would get hungry.”
The Flat Belly Diet: Short-Term Effects and Long-Term Effects
People who are on the Flat Belly Diet will lose weight, but most of it will be water weight. And while the Mediterranean-style diet is healthy, long-term weight loss will also need to involve exercise, lifestyle adjustments, and perhaps working with a nutritionist, particularly if you are someone who needs fewer or more than 1,600 calories.