What’s the theory?

This diet shares its theory with the Atkins plan. By limiting carbs, blood sugar levels are controlled, which in turn, reduces the amount of insulin that’s released into the blood stream. This encourages the body to burn fat as its main source of energy with the result that weight loss occurs. Through helping to control insulin levels, this diet also prevents or treats a condition called Syndrome X or insulin resistance, which makes us vulnerable to being overweight or obese, and gives the book it’s title.

What does the diet involve?

The X-Factor Diet is similar to the Atkins diet. There are two programmes to follow – Ketogenics or Insulin Balance – depending on how much body fat you have to lose. Both are effectively low-carb, high-protein diets but Ketogenics is the stricter plan of the two and is only suitable for women with more than 35 percent body fat and men with more than 22 percent body fat. Ketogenics limits carbs to a tiny 20g a day (most of us eat 250-300g a day) and recommends 50 percent of calories come from protein, 20 percent from carbs and 30 percent from fat. Insulin Balance is lower in protein and higher in carbs with 35 percent of calories coming from protein, 35 percent from carbs and 30 percent from fat.

What can I eat?

As with the Atkins diet, high-carb foods like bread, potatoes, pasta, rice, cereals and beans are out, although more fruit and veg are allowed on the Insulin Balance plan. Palm sized portions of lean meat, chicken, fish and eggs are allowed and the emphasis is on choosing fats that are rich in heart-healthy monounsaturates rather than filling up Atkins-style on cream, butter and fried food.

How much weight will I lose?

With the strict plan, women can expect to lose 4-12lb and men, 8-16lb in two weeks. After this, weight loss slows to 1/2-2lb.

What else does the book include?

Lots of theory about why low-carb, high-protein diets work, a 14-day diet for each plan, recipes and detailed information about Syndrome X.

Juliette’s verdict on the X-Factor Diet

This has a lot of similarities to the Atkins Diet. Whichever plan you follow, the balance of the diet is still a long way from current healthy eating guidelines that recommend 15 percent of our calories should come from protein, 50 percent from carbs and 35 percent from fat. Meanwhile, there’s still not enough evidence to prove that low-carb diets work any better than reduced-calorie diets to aid and maintain weight loss.

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