The Flat Belly Diet is designed for rapid weight loss. Creators Liz Vaccariello and Cynthia Sass claim you can lose up to 15 pounds and belly fat in 32 days by following the diet.
The diet philosophy is that monounsaturated fatty acids (MUFAs), the fats found in plant sources, help you lose fat while still feeling full and eating the foods you love.
While the diet is primarily aimed at women, they also offer a male version that allows for increased caloric consumption. There are three other dietary fats found in foods to be aware of: saturated fats, trans fats, and polyunsaturated fats.
Polyunsaturated fats are also considered “healthy fats.” However, they are not the focal point of this diet. Trans fats and saturated fats should be consumed in moderation or avoided, given their detrimental health impacts.
How Flat Belly Diet Works
The Flat Belly Diet is split into two phases over 32 days.
You target midsection bloating by consuming 1,200 calories per day during the first phase. This is achieved through four meals at 300 calories each, followed by four weeks of three meals a day at 400 calories each and 400 calories from snacks.
Exercise is not a diet requirement, but it is strongly encouraged. The book, Flat Belly Diet! provides exercise workout plans to inspire you with a balance of cardiovascular exercise to burn stomach fat alongside strength training to build muscle and boost metabolism.
The Diet Plan
The Flat Belly Diet plan resembles the Mediterranean diet — lots of whole grains, seafood, vegetables, olive oil, and beans. Dark chocolate and red wine are also allowed.
Some aspects of the diet can be expensive, given the ingredients such as nuts, olive oil, and fish. Legumes are generally quite affordable, so you can choose to incorporate these more to make this diet more budget-friendly. Given that it is only carried out over 32 days, the increased costs won’t significantly impact the long term.
Dos and Don’ts
During the first four-day phase, you cannot consume added salt, processed foods, high-carb foods like white bread and pasta, or stomach-bloating foods such as beans. The diet also recommends eating certain foods like vegetables cooked rather than raw. Throughout the diet, you must not go four hours without eating and incorporate healthy fats (monounsaturated fats) at every meal.
Sample Diet Plan:
Breakfast: Mango smoothie
Lunch: Chickpea Soup
Snack: Handful of nuts
Dinner: Salmon and avocado salad
Health Benefits and Drawbacks
The health benefits of the Flat Belly Diet are pretty extensive, given its foundation in the Mediterranean diet, which has been widely researched.
- Reduced risk of Alzheimer’s and Parkinson’s Disease
- Reduced risk of coronary heart disease
- Lower your total cholesterol, particularly “bad” cholesterol
- MUFAs slow digestion, enabling you to feel fuller for longer
Rapid weight loss is mainly through the loss of water rather than fat. It can also lead to muscle loss.
Not sustainable. Rapid weight loss is not as sustainable (they suggest you can lose up to 15 pounds while on the diet!). When the diet is not part of an ongoing lifestyle, it can be challenging to maintain its long-term benefits.
No variation. The caloric intake is strict and doesn’t account for individual differences—as a sedentary individual may have a very different energy intake requirement when compared with someone who exercises regularly.
Other drawbacks include:
- In the initial phase, restricting to 1,200 calories per day can lead to side effects, including dizziness, nausea, and fatigue.
- The diet may not provide sufficient calcium intake.
The Bottom Line: Is the Flat Belly Diet a Healthy Way to Lose Weight?
Overall, we think that the flat belly diet has the potential to be an effective way to lose weight quickly.
However, given that it’s only 32 days, we recommend coming up with a structured plan so that your weight doesn’t bounce back once you come off the diet. For example, this could mean gradually increasing your caloric intake while still eating similar, healthy foods to strike a balance and maintain your target weight long term.
Meagan Morris is the editor in chief of Celebribody. She's veteran health and wellness editor with over 15 years of experience. Her work has been featured in The Atlantic, Yahoo Health, Cosmopolitan, SELF, and Women's Health, among others. She spends most of her time writing, but her favorite part of the day is spent under a barbell doing squats.