The authors base their book principally on some Spanish research from 2007 presented in the journal Diabetes Care, which suggested that people who ate more MUFAs (Monosaturated Fatty Acids) lost more belly fat than people who ate the same number of calories but more saturated fats or carbohydrates.

MUFAs are an integral part of the excellent Mediterranean Diet. Common MUFAs include: olive oil; nuts and peanut butter; nut oils such as peanut and sesame oil; seeds such as sunflower and pumpkin; avocado; and perhaps dark chocolate.

I summarize the Flat Belly Diet book:

1.    Eat four— 400 calorie meals per day, 1600 calories total (for a woman); meals spaced 4 hours apart
2.    Eat a MUFA with each meal

They describe a four-day “Jumpstart” followed by a four-week “Eating Plan”, and claim you don’t really have to exercise to slim your belly. The online program at FlatBellyDiet.com screams: “91% Success Rate! Target Belly Fat….NO exercise required!”. It’s interesting the book and website overwhelmingly targets women, but it’s the men who generally need more help with belly fat problems. But many more women than men buy diet books…

Flat Belly Diet is strong on marketing hype, though it scores good points emphasizing MUFAs. However the research on MUFAs leading to a special loss of abdominal fat is preliminary, controversial, and based on relatively few subjects (there were only 11 “volunteers” in the main study). Nevertheless, some people only attempt a dietary change with a glitzy book filled with recipes and a “plan”, so if that’s you, maybe this book is worth looking at.

But if you are really serious about affecting a more long-term change in your diet, and don’t care about glitz and bling, I would recommend a more thoughtful and scientific book: Michael Pollan’s In Defense of Food. It’s cheaper and a much better value than the flashy Belly book. I love how Pollan puts forward three basic laws of a good diet: “Eat food. Not too much. Mostly plants.” He emphasizes avoiding processed foods and sticking to foods “your grandmother would recognize”. Simple advice—lacking the high production value in many diet books today—is often the best.