If the body needs energy and can't burn fat because of high insulin levels, a person feels tired as their brain starves and metabolism slows to compensate. This occurs because the brain runs on glucose and high insulin levels deplete blood glucose levels. Such condition, rebound hypoglycemia causes sweet cravings (which just starts the high-insulin cycle all over again).Sears describes a Zone meal as follows: "Eat as much protein as the palm of your hand, as much nonstarchy raw vegetables as you can stand for the vitamins, enough carbohydrates to maintain mental clarity because the brain runs on glucose, and enough monounsaturated oils to keep feelings of hunger away." Comparison to low-carb diets:The Zone is considered a low-carb diet. It is not as restrictive in total carbohydrate intake as some of the other low-carbohydrate diets (e.g. the Atkins diet) that became extremely popular throughout the United States in 2003 and 2004. Sears claims these other diets miss the point.


According to him, they ignore the importance of hormonal balance, as well as the influence of dietary balance on digestion and hormone production. Specific cases: Italy:The introduction of the Zone in Italy began in 1997 by a physician, Aronne Romano M.D. who applied this nutritional style to patients and athletes. Since the 2nd edition of the book "Come Raggiungere la Zona" (The Zone), in 1999, the Chef Memo Romano and his brother Aronne modified the original recipes and menu to suit the local food and habits. Famous obesity case:Possibly the most famous case of someone using the diet effectively has been Mexican Manuel Uribe. After weighing in at around 560 kg (1234 lbs or over 88 stone) but within 2 years had lost about 260 kg..After decades of failed weight loss methods, including a botched liposuction that nearly killed him, devotion to the Zone Diet has been the only weight loss program to have such a positive impact on the Mexican man, whose weight once topped 1,200 lbs.


Dr. Barry Sears, along with two of Mexico's most prestigious physicians, Dr. Silvia Orozco Avina and Dr. Gustavo Orozco Avina, are at the helm of the interdisciplinary team of doctors, nutritionists and exercise physiologists who continue to work diligently to help Manuel reach his goal . . . and his birthday.Manuel's current diet consists of about 2,000 calories per day broken up into six meals. His specially designed menu includes a wide variety of meals including egg-white omelets, fresh salads, chicken fajitas and fish filet in a bed of spring greens. In fact, Manuel's biggest problem is not lack of appetite control, but eating all the food he is supposed to eat.Despite his weight, Dr. Sears considers Manuel one of the healthiest men in Mexico. He is not at risk for diabetes, and his blood pressure and triglyceride levels are normal. In addition, his resting heart rate averages 62 beats per minute, a level usually found in trained athletes. Even though Manuel is confined to his bed, his medical team designed a tailored exercise regimen that includes sit-ups, pull-ups and hand-biking to help build muscle mass and accelerate fat loss.

The Zone Diet

The Zone diet is a diet popularized in books by biochemist Barry Sears. It advocates consuming calories from carbohydrates, protein and fat in a ratio of 40%/30%/30%. Theory:The diet centers on a "40:30:30" ratio of calories obtained daily from carbohydrates, proteins, and fats, respectively. The ideal formula has been under debate, although studies over the past several years (including a non-scientific study by the PBS documentary show Scientific American Frontiers) have shown that it can produce weight loss at reasonable rates. The Scientific American Frontiers study compared the effectiveness of several popular 'diet' regimes including the Zone; somewhat to the surprise of the show's staff, the participants on the Zone experienced the greatest fat loss while simultaneously gaining muscle mass. Participants also reported the Zone as the easiest regime to adjust to, i.e. having the fewest adverse affects such as fatigue or hunger. Most people who report fatigue find that the fatigue diminishes by day 2 or 3.

"The Zone" is Sears' term for proper hormone balance. When insulin levels are neither too high nor too low, and glucagon levels are not too high, then specific anti-inflammatory chemicals (types of eicosanoids) are released, which have similar effects to aspirin, but without downsides such as gastric bleeding. Sears claims that a 30:40 ratio of protein to carbohydrates triggers this effect, and this is called 'The Zone.' Sears claims that these natural anti-inflammatories are heart and health friendly.Additionally, the human body in caloric balance is more efficient and does not have to store excess calories as fat. The human body cannot store fat and burn fat at the same time, and Sears believes it takes time (significant time if insulin levels were high because of unbalanced eating) to switch from the former to the latter.citation needed Using stored fat for energy causes weight loss.Another key feature of the Zone diet, introduced in his later books, is an intake of a particular ratio of Omega-3 to Omega-6 fatty acids.


Dr. Sears is believed to have popularized the taking of pharmaceutical grade Omega 3 fish oils. Hormonal paradoxes:Sears emphasizes a hormonal paradox contrary to the "low-fat" rationale, namely that low-fat diets increase the production of the hormone insulin, causing the body to store more fat. The example proposed by him is the cattle ranching practice of fattening livestock efficiently by feeding them lots of low-fat grain. He and others also point out the supposed irony that human diets in the West for the last twenty years have been full of low-fat carbohydrates, yet people are considered more obese now.Additionally, Sears suggests fat consumption as essential for "burning" fat.His rationale is: Monounsaturated fats in a meal contribute to a feeling of fullness and decreases the rate at which carbohydrates are absorbed into the bloodstream. Slower carbohydrate absorption means lower insulin levels which means less stored fat and a faster transition to fat burning.