Search and Hit Enter

The diet series: Intermittent Fasting and The Zone diets

Intermittent Fasting Diet

There are different types of fasting diets, some including fasting during the day, others alternating days in which you don’t eat with days in which you eat, and then there is also the 5.2 fasting diet. The 5:2 diet, also called The Fast Diet or Intermittent Fasting Diet (or intermittent eating diet, depending on point of view) is a type of intermittent fasting known as alternate-day fasting. Basically, on this diet, you eat normally for five days a week and restrict your daily calorie intake to 500–600 kcal (basically just implies you reducing the amount of calories) for two days every week, resulting in an overall calorie deficit that leads in the end to weight loss. The 5:2 diet is seen as an improved alternate-day fasting diet. By contrast, some other types of alternate-day fasting diets involve going without food for a full 24 hours. The 5:2 diet has extremely low calorie allotment on the two days you have to fast.

Evidence supporting the health benefits of alternate-day fasting is growing by the day, and it seems to be a legitimate and healthy option for weight loss.

Research suggests that alternate-day fasting doesn’t cause excessive calorie intake on eating days despite what you would think.

This may be also due to the release of peptide YY (PYY), which is a hormone that makes you feel full and therefore helps you eat less. However alternate-day fasting hasn’t been shown to cause a greater amount of weight loss when compared to standard diets containing the same number of calories, several studies have found that both approaches (calories restriction and alternate fasting) can be effective for losing weight and belly fat. Moreover, although it isn’t possible to completely prevent loss of muscle while losing weight, alternate-day fasting seems to be more preventive in this aspect as it helps maintaining muscle mass when compared to conventional forms of calories restriction and this is per se an advantage. Summarising, the 5:2 diet is a form of alternate-day fasting that involves eating 500–600 kcal two days a week and eating normally otherwise, therefore, no stress on no-fasting days. It’s been found effective for losing weight and fat while having some protection against muscle loss.

The Zone Diet

The Zone diet was created in the mid-1990s by Dr. Barry Sears, a US-based biochemist. He developed this diet after losing a family member who died prematurely of heart attack. The Zone diet is thought to have an anti-inflammatory effect in your body. One of the pillars of the diet is that once you reduce generalised inflammation, you will lose fat at the fastest rate possible, slowing down ageing, and therefore reducing your risk of chronic disease and improvement of your overall performance. It’s based on the premise that a strict ratio of protein:fat:carbs is required for optimal weight loss and overall health.

This eating regime specifies that the overall calorie intake should be made up of 30% lean protein, 30% healthy fat and 40% high-fibre carbs.

As part of this specific diet, carbs should have what is called a low glycemic index, which means it should provide a slow release of sugar into the blood to keep you fuller for longer. Protein should be mostly lean and fat should be mostly monounsaturated (found in organic meat or healthy vegetable oils).  In addition, these foods should be consumed as a prescribed number of “blocks” at meals and snacks. It seems that what is called the “hand-eye” method is the easiest way to start the Zone Diet. As the name suggests, your hand and eye are the only tools necessary to get started, although wearing a watch can be useful to keep an eye on when to eat (as it should be at a specific time of the day). In this approach, your hand has several uses. You basically use it to determine your portion sizes. Your five fingers are your reminder to eat five times a day and never go without food for more than five hours. In the meantime, you use your eye to estimate portions on your plate. For example, to design a Zone-friendly plate, you need to divide your plate into thirds.

  • One-third lean protein: One-third of your plate should have a source of lean protein, more or less the size of your palm.
  • Two-thirds carbs: Two-thirds of your plate should be carbs with a low glycemic index.
  • A little bit of fat: Add a little bit of monounsaturated fat to your plate, such as avocado or almonds or olive oil.

This method is designed to be a simple way for a beginner to follow the Zone Diet. It is very flexible and also allows you to eat out at restaurants while you are following the Zone Diet, because you can use your hand and eyes as specific tools to choose options that fit Zone recommendations. Then, Zone food blocks allow you to personalize your diet to your body by calculating how many grams of protein, carbs and fat you can have/need per day. The number of Zone blocks you should eat per day depends on your height, weight, waist and hip measurements. The average male eats something like 14 Zone blocks per day, while the average female eats usually 11 Zone blocks. A main meal such as breakfast, lunch or dinner contains three/five Zone blocks, while a snack always contains only one Zone block. Each block is of course made of a protein block, a fat block and a carb block. Blocks are usually divided like this:

  • Carb block: Contains more or less 9 grams of carbs.
  • Protein block: Contains more or less 7 grams of protein.
  • Fat block: Contains more or less 1.5 grams of fat.

Studies to date suggest that the Zone diet can be effective for weight loss and reducing the blood sugar levels, insulin resistance and also inflammation. In a controlled, six-week study with overweight adults, those who followed the Zone diet lost more weight and body fat compare to the low-fat diet group. On top of that they also reported in average 44% reduction in fatigue. In another study, 33 people followed one of four different diets. The Zone diet was shown to help participants lose the most fat, and to increase the ratio of anti-inflammatory omega-3 fatty acids to omega-6 fatty acids at the end of the study.

By Ornella Cappellari