Between 2007 and 2008 in the United States, 34 percent of adults over the age of 20 were overweight and another 34 percent were obese, according to the National Center for Health Statistics. A person is considered overweight if her body mass index is between 24 kg/m2 and 30 kg/m2; a person with a body mass index of 30 kg/m2 or higher is considered obese. While Americans may be gaining weight, their brains are starving, according to Larry McCleary, MD, a neurosurgeon and author of the book Feed Your Brain, Lose Your Belly. McCleary explained that the foods Americans typically eat – the ones that contribute to the weight gain we have seen rise over the years – do not provide the nutrients that the brain needs, causing it to starve. With the diet proposed in Feed Your Brain, Lose Your Belly, he claimed that people can, as the title said, lose the weight around their waistlines and get the nutrients their brain needs.
The book is written for the layperson – while it covers complex material, the material is well explained for people who do not have a background in medicine, nutrition or neuroscience. For readers who have more advanced background knowledge, McCleary provided a section at the end of the book that goes over the clinical trials mentioned in the book. McCleary clearly laid out the connection between our brains and our bellies: it is the brain that sends the signal when we are hungry, and when we are not consuming food, the brain relies on the belly for energy. He explained insulin affects how we store and use fat cells: when insulin levels are elevated, our bodies store fat, but when insulin levels return to normal, we can use the fat stored as energy. The problem arises when we consume food that keeps the insulin levels high – even if we need the energy from the stored fat, the high insulin levels keep our cells in fat storing mode. McCleary illustrated these effects by showing how people responded to different diets. For example, in a calorie-restricting low-fat diet conducted by Ancel Keys in 1944, participants ate about half the amount of calories they normally did, with 57.3 percent of calories coming from carbohydrates, 25.4 percent from protein and 17.2 percent from fat. The participants in this diet study lost about a pound each week but were always hungry. In comparison, Per Hanssen conducted a calorie-restricted higher-fat diet in 1936 in which participants ate 1,850 calories, with 60 percent of calories coming from fat, 25 percent from carbohydrates and 15 percent from protein. The participants in this study lost about two pounds each week, and unlike the other study, did not feel hungry.
McCleary argued that diets that cut out all fats are causing more harm than good, stating that a balance is needed for the brain to get the nutrition it needs. He explained that when we eat a meal with both carbohydrates and fat, the carbohydrates get broken down into glucose – which the brain needs – and the fat gets sent to storage. But when the insulin levels drop down, our bodies can use that fat from earlier. Diets that have a higher carbohydrate to fat ratio keep our insulin levels elevated much longer, preventing our bodies from using any stored fat, storing it instead. But as McCleary noted, not all fat is good fat: for example, essential fats, such as omega-3 fatty acids, which are found in fish and walnuts, are the ones that are needed, not trans fats. Besides causing weight gain, McCleary pointed out that eating diets that do not provide the nourishment the brain needs can cause serious problems for the brain. For example, too high insulin levels can cause low blood sugar, which when severe can cause brain fog.
Toward the end of the book, McCleary provided a seven day meal plan with breakfast, lunch and dinner for each day, as well as dessert. He broke down the calorie content by fat, carbohydrate and protein and gave easy-to-follow cooking instructions. He also has chapters on exercise to accompany the diet, as well as chapters dealing with the mind-body challenges of losing weight. This is more than just a diet book and may be helpful for people who do not want to lose weight but want a healthy brain.
Note: the author received a free review copy of the book from the PR firm representing the author
National Center for Health Statistics. FastStats: Obesity and Overweight. Centers for Disease Control and Prevention, 2010. Web. 29 June 2011
A.D.A.M. Obesity. MedlinePlus, 2011. Web. 29 June 2011
Larry McCleary. Feed Your Brain, Lose Your Belly. Greenleaf Book Group Press, 2011.
Reviewed June 29, 2011
Edited by Alison Stanton