The Zone Diet was developed by American medical researcher Barry Sears. Its main aim is controlling the hormones of the body by eating lean protein and unprocessed foods in order to achieve weight loss. While the logic makes sense, does this diet really work? We take a closer look.
How Does The Zone Diet Work?
The Zone Diet is pretty complicated, and to follow it properly you would need to do a lot of research into macronutrients, hormones, and blood sugar.
When following the Zone Diet, meals are split into 'blocks'.
7 grams of protein = 1 block. 14 grams = 2 blocks. 21 grams = 3 blocks.
9 grams of carbs = 1 block. 18 grams = 2 blocks. 27 grams = 3 blocks.
1.5 grams of fat = 1 block. 3 grams = 2 blocks. 4.5 grams = 3 blocks.
A one block meal would consist of one block of protein, one of carbs, and one of fat. There are then two block meals which are two portions of each, three block meals which are three portions, and so on. The blocks work on the rule of consuming 40% carbohydrates, 30% protein, and 30% fat at every meal.
Followers of the diet are encouraged to eat at regular intervals in order to keep the hormone levels balanced and to weigh out their food. The Zone Diet classifies carbohydrates by the Glycemic Index which rates them according to how quickly they raise the blood sugar. Slowly-absorbed carbohydrates have a low GI rating (55 or below), and include most fruits and vegetables, milk, some wholegrain cereals and bread, pulses and basmati rice. The Glycemic Index is usually used by diabetics to manage their insulin levels.
The logic of controlling the body's hormones in order to lose weight and stay healthy is a great one. Many people do not realise the effects that their nutrition has on their hormones and the effect that those hormones have in turn on their mood, weight, and other lifestyle factors. The Zone Diet focusses on three key hormones: glucagon, insulin, and eicosanoids. Glucagon tells the body to release stored carbs at a steady rate which stabilises blood sugar levels. Insulin is the storage hormone and an excess can cause excess weight gain. Eicosanoids control various other hormones in the body.
This diet also encourages people to weigh their food and eat at regular intervals which are excellent healthy eating habits. The macronutrient split is not as harsh as other people may insinuate, as 40% carbs is really not that low.
For a start, this diet is probably too confusing for most people to follow, and when people can't understand something they won't stick with it. Another major flaw with this diet is that it classifies carbohydrates in a way that would tar tomatoes with the same brush as rice or pasta, even though they have a completely different effect on the body. This diet implies that a portion of vegetables would count towards as many carbs as a bowl of porridge or something similar, which simply isn't true.
Additionally, this diet encourages people to cut corners. One source states that if a snack bar were to contain 8g of protein, 29g of carbohydrates, and 6g of fat, you would only count the carbs and so this snack bar would be a '3 block carbohydrate' which we can clearly see it isn't. The block system over-simplifies counting macronutrients, and rounding down 8g of protein and 6g of fat to zero is not a good habit to get into as it'll lead to overeating and frustration.
While the roots of this diet make sense, the execution is very poor and it risks leading people into bad habits. For those who have no prior understanding of nutrition, macronutrients, or hormones, this diet would be far too complicated and could lead to them becoming wildly misinformed. Weight loss and healthy living do not have to be complicated! Eating healthy, whole foods in moderation and not exceeding your daily calorie allowance is all you need.