Flat Belly Diet! Does It Fall Flat on Its Promises?

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Flat Belly Diet! Does It Fall Flat on Its Promises?

Author: Betty Kovacs, MD, RD
Medical Editor: Melissa Conrad Stöppler, MD

Flat Belly Diet!

What grabs your attention when looking for a diet to follow? Do phrases like no exercise required, fast weight loss, never feel hungry, easy to follow, guaranteed results, and no deprivation required come to mind? Most of the popular fad diets make these promises up front but end up reneging on them once you read the details of the diet. I have read the new diet book Flat Belly Diet! and will give you the pros and cons about this diet along with the facts about what the research says about successful weight loss.

The Flat Belly Diet! program promotes eating a reduced calorie diet that is high in monounsaturated fat (MUFA) in order to flatten your belly with no exercise required. The diet is 32 days long. It states that studies show that this is "just enough time to make any dietary change a lifestyle." I have not seen any studies stating this fact. Some people may find this to be the case, but the majority of the people whom I have worked with need much longer than 32 days to develop new eating habits. It's important to know that there is nothing wrong with needing more than 32 days to make changes to your diet.

The book begins with a detailed discussion about the two primary types of body fat: subcutaneous and visceral fat. The subcutaneous fat is the fat underneath your skin, and the visceral fat is the inner fat that surrounds your organs. There is no disputing the fact that visceral fat is the most dangerous one for our health. The error that this diet makes is stating that it's the most difficult fat to lose and that the only way to minimize it is to eat the right kind of fat. Visceral fat is actually easier to lose than subcutaneous fat and can be lost without any changes to your diet. In fact, studies have shown a reduction in visceral fat with moderate exercise and very little weight loss. Research shows that the ideal approach to decreasing visceral fat is to focus on increasing your activity level, decreasing your intake of sugar and refined carbohydrates, consuming complex carbohydrates and lean meats in place of refined carbohydrates, limiting your intake of alcohol, and consuming polyunsaturated and monounsaturated fats in place of saturated and trans fats. Unfortunately, this diet only focuses on monounsaturated fats (MUFA).

Throughout the book there are stories about people who have been successful with this diet. Their weight loss and inches lost around their waist are mentioned, but their visceral fat changes are not discussed. The reason for this is that it takes very expensive tests to show changes in visceral fat levels. Therefore, there is no evidence about the kind of fat lost or how much muscle was lost with this diet.

Quick GuidePortion Control Tips: Lose Weight and Stick to Your Diet

Portion Control Tips: Lose Weight and Stick to Your Diet

Monounsaturated fats (MUFA) are the dietary foundation for this plan. The claim is that these fats will fill you up and reduce your belly fat. The first inaccuracy is the premise that dietary fat will fill you up. Numerous studies have shown that fat has no impact on satiety. The only nutrient that has been proven to increase satiety, and thus keep you full between meals, is protein. There is not one mention of this in this book. I can promise that without an adequate amount of protein in your meal, you will be hungry soon after eating. I have worked in the weight-loss field for over 10 years and find this to be one of the keys to my clients' staving off their hunger.

The emphasis on monounsaturated fats comes from one study that is cited in the book. It showed that a diet rich in monounsaturated fat can prevent weight gain in your belly. This study only had 11 people in it and compared the monounsaturated-fat diet to a high-carbohydrate and a high-fat diet for a period of only 28 days. A limitation to this study is that they did not differentiate among the kinds of carbohydrates consumed. As I previously mentioned, one of the goals for visceral-fat reduction is to consume a diet that is high in complex carbohydrates and low in sugar and refined carbohydrates.

The other limitation to this study is that they did not have anyone following a diet that was high in polyunsaturated fats. Research has shown that a diet high in the polyunsaturated omega-3 fats can decrease abdominal fat. Omega-3 fats have been receiving a lot of attention lately because of the positive impact they have on health. Omega-3 fats' health benefits include reducing the risk of stroke and heart disease and decreasing the symptoms of hypertension, attention deficit hyperactivity disorder (ADHD), depression, joint pain and other rheumatoid problems, as well as certain skin ailments. The research has been so compelling that the American Heart Association now has recommendations for how much omega-3 fat we need to consume. For those who do not have any documented heart disease, the recommendation is to consume at least two servings of fatty fish each week. You can also use flaxseeds, canola oil, walnuts, laxseeds, and soybean oils as sources. For those who have heart disease, the recommendation is to consume 1 gram per day. Omega-3 fats are briefly mentioned in this book but are not emphasized as part of this diet. With the average American diet being too low in this essential fat, this is a grave limitation with this diet.

The Four-Day Anti-Bloat Jumpstart

The first part of this diet is called the Four-Day Anti-Bloat Jumpstart. The book states that "in just four days, you'll lose several pounds and inches" and it promises to "shrink your belly-a loss of up to 5 ¾ total inches." The premise for this is to get you motivated to proceed with the remainder of the diet by seeing some results happen quickly. The goal for these four days is to eliminate gas, heavy solids, and excess fluid. A 1,200-calorie diet is given with the instruction to avoid

  • salt,


  • excess carbs,


  • raw bulky foods,


  • gassy foods,


  • chewing gum,


  • sugar alcohols,


  • fried foods,


  • spicy foods,


  • carbonated drinks, and


  • alcohol, coffee, tea, hot cocoa, and acidic fruit juices.

Those following this plan are also instructed to take a five-minute after meal walk.

The calorie goal for this is low for the average woman who needs to lose weight. In fact, the calorie goal for both parts of this diet is not ideal for long-term success. Your calorie needs are based on your height, weight, age, gender, and activity level. It's always best to determine your own needs and use that as your goal. In order to lose weight, you need to consume fewer calories than your body needs. When you cut out 3,500 calories from your maintenance calories, you lose one pound of body weight, not body fat as stated in this book. The way to determine your calorie needs is to get your maintenance needs and subtract 500 calories per day to lose 1 pound per week (500 x 7 days = 3,500 calories) or subtract 1,000 calories per day to lose 2 pound per week (1,000 x 7 days = 7,000 calories).

The guidelines to lose 1 to 2 pounds per week are set so that you lose an optimal amount of fat and muscle. Each pound that we gain from eating an extra 3,500 calories contains 75% fat and 25% muscle. Many people believe that you only gain fat, but that is not the case. When you lose weight, you will also lose fat and muscle. The recommended 1- to 2-pound per week weight loss is set so that you lose what you gained: 75% fat and 25% muscle. The faster that you lose weight, the more muscle and the less fat you will lose. So, if your maintenance calories are 2,800 and you consume 1,200 calories, you are going to lose more muscle than fat, especially with a plan that does not require any resistance exercise.

I also think that this part of the diet could be a trigger for many people. Studies have shown that deprivation when trying to lose weight does not help. People either end up consuming too much of something else or overeating the food that they were trying to avoid. This is also a temporary fix. The bloating can easily return once any of the omitted foods or beverages are added back. You can use these suggestions as part of your daily intake to limit the amount of foods that could contribute to fluid retention without having to omit everything.

The Four-Week Eating Plan

The primary part of this diet begins after the initial four-day diet. This part will last for 28 days. The 1,600-calorie requirement is set based on a "40+ woman of average height, frame size, and activity level to get to and stay at her ideal body weight." Again, this calorie level is not going to be ideal for everyone. The guidelines for this part are

  • eat monounsaturated fat at every meal,


  • consume 400 calories per meal, and


  • never go more than four hours without eating.

There are lots of recipes that you can choose from for each of the 400 calorie meals. They do not list the fat, carbohydrate, or protein content of any of these meals. There is also no fiber count listed. Dietary fiber is essential for every one of us. Contrary to what the book says, some fiber is absorbed, so it can add calories to your diet. The health benefits of fiber far outweigh the small amount of calories that you would actually absorb.

Quick GuidePortion Control Tips: Lose Weight and Stick to Your Diet

Portion Control Tips: Lose Weight and Stick to Your Diet

Some people may have a hard time with consuming 400 calorie meals all day and/or eating every four hours. The emphasis on consuming breakfast is correct, but you may find that you prefer to break your calories up differently. It's important to follow an eating plan that fits your lifestyle or that feeling of being "on a diet" will take over. What matters most is reaching your recommended amount of calories for the entire day by eating at least three meals with a balance of foods from each of the food groups.

There is some discussion about the emotional component of eating and the need to monitor what you consume and how you are feeling. Let's face it, there is a lot that impacts what, when, why, and how much we eat. Some people need more support and guidance on making this behavior change than what is covered in this book.

Though the cover of the book states that "not a single crunch is required" in order to flatten your belly, there is a chapter devoted to exercise. I like the suggestion that is made that it can be better to focus on changing one thing at a time. I completely agree with focusing on your diet first. I just think that the claim that is initially made can be misleading. The research is clear that the single best predictor of keeping your weight off is exercise. There are going to be people who can lose some inches from their waist through dietary changes but will not be able to "flatten" their belly without exercise.

The quick fix or that "magic" nutrient that you add or remove from your diet is not what it takes to achieve long-term success with weight loss. The National Heart, Lung, and Blood Institute's Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults states that successful weight loss and maintenance requires diet, physical activity, and behavior modifications. The goal needs to be making changes that you can maintain so that you do not put back on the weight that you lost. While this book provides some useful recipes and information about body fat and monounsaturated fats, it is probably not going to help you achieve long-term success with weight loss if you have a substantial amount to lose.


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Reviewed on 3/24/2008

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