Zone Diet

What is the Zone Diet

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. 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. 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."

What does the Zone Diet involve?

If the theory sounds simple, the reality is far more complicated. First off, you’ll need plenty of patience, a head for science and the desire to learn more about ‘zoning’, either by looking at the Zone website or indulging in some bedtime reading, courtesy of creator Barry Sears.

The idea is that to reach ‘The Zone’, every meal and snack should provide 40 percent of calories from carbohydrate, 30 per cent from protein and 30 per cent from fat. This is what some Zone fans call the 40:30:30 ratio.

To help with this, ‘Zone Food Blocks’ have been developed, where each ‘block’ contains a standardised amount of carbohydrate, protein or fat. To lose weight, a certain number of blocks are allocated for each meal and snack.

The number of Zone Food Blocks you should have each day is calculated according to your weight, height and waist and hip circumferences. Generally, the bigger you are, the more blocks you are allowed. For example, a woman who weighs 10st, is 5ft 2in, has a 28in waist and 37in hips should have 12 blocks a day (four for breakfast, three each for lunch and dinner, one for an afternoon snack and one for an evening snack). Meanwhile, a larger woman who weighs 12st, is 5ft 10in, has a 30in waist and 40in hips needs 14 blocks (four for each main meal and one each as an afternoon snack and an evening snack).

With help from Weight Loss Resources or the Zone’s website, Zone Perfect, calculating the daily number of blocks you should have – and how they should be divided throughout the day – is the easy bit. Creating meals and snacks that have the correct number of Zone Foods Blocks is the hard bit! No surprises then that you really need a Zone Diet book to help you put meals together. And if that’s still too much like hard work, there are many pre-packaged Zone Diet meals and snacks for delivery that you can order over the Internet – at a fairly hefty price!