Although the creator of the diet is quite adamant that for best effect you should really stick to counting Food Blocks, it’s still possible to follow the basic principles of the diet without going through this complicated process.

In simple terms, the Zone diet involves cutting out most carbohydrates such as breakfast cereals, rice, potatoes, pasta, noodles, bread, bagels, croissants, muffins, crisps, pastries, pies, chocolate, sweets, sugar and preserves, as these have the greatest effect on blood sugar levels and therefore insulin levels. Most fruit and vegetables, however, are allowed. Low-fat protein-rich foods such as skinless chicken, turkey and fish should be eaten with every meal. Meanwhile, eating fewer foods that contain saturates and choosing foods that are rich in monounsaturates, such as olive oil, avocado and nuts, is recommended.

To make the Zone Diet even easier to follow, the creator recommends dividing your plate into three equal sized sections and then filling one section with low-fat protein such as chicken - making sure it’s no larger or thicker than the palm of your hand - and the remaining two sections with vegetables and fruit. Adding a little olive oil, avocado or a few nuts will help to boost intakes of monounsaturates.

Advocates of the Zone Diet claim you can lose at least 5 lb in the first two weeks, followed by 1-1.5 Ib every week after this.

Achieving a 40:30:30 ratio is certainly a departure from current healthy eating guidelines, which recommend 50 percent of our calories should come from carbohydrate, 15 percent from protein and 35 percent from fat. While most nutrition experts agree with the advice to eat less fat, especially saturates, and to fill up on fruit and veg, most remain skeptical about the theory that weight loss is due to regulating insulin levels. They still believe that eating fewer carbohydrate-rich foods results in a calorie deficit. In other words, any weight loss that occurs is due to taking in fewer calories than the body uses up. In fact, if followed properly, the diet provides around 1,000 to 1,300 calories a day, thanks mainly to cutting out most high-calorie sugary and starchy foods - and replacing them with low-calorie vegetables and fruit. And if you’re still not convinced, maybe this example will help: swap a large Danish pastry, containing around 650 calories, for a 50-calorie apple and you’ll save a staggering 600 calories. Do this every day for a week and you’d expect to lose more than 1 Ib in a week!
 

The Zone Diet generally has fewer dietary restrictions than many other low-carb plans and recommends eating more fruit and vegetables. It also encourages you to cut out a lot of the ‘junk’ or low-nutrient carbs in your diet such as crisps, cakes, biscuits and chocolate. Eating fewer fatty foods - and swapping foods that are high in saturates for those containing monounsaturates - is sensible, heart-healthy advice, too.

Unfortunately, the Zone Diet is very complicated and time-consuming, if you’re going to follow it properly. You’ll need to invest in a Zone diet book and a decent set of measuring scales and spoons if you don’t already have them. It also recommends eliminating some very nutritious foods, which are not only a good source of carbohydrate but are also packed with fibre and important vitamins and minerals. For example, wholegrain cereals are packed with fibre, B vitamins and iron, while cheese is an excellent source of calcium and zinc. It can also be really expensive if you decide to purchase pre-packaged Zone products! As for eating out, if you’re counting Food Blocks, you might as well forget it.