A relatively new entrant into the world of fasting, the 5:2 Diet aims to do away with the feelings of deprivation and struggle that people so often experience in traditional dieting. Instead, it encourages a modified fasting program in which fasting days are spent, not in completely abstaining from food, but in significantly restricting caloric intake.
The goals of this article are to give you a better understanding of the 5:2 Diet and its origins, as well as take a look at what foods you should and shouldn’t be consuming on and off your fasting days, why the glycemic index is especially important for this type of fasting, and strategies on how to stick to the calorie limits set for your fasting days.
Unlike other fasting methods, the 5:2 Diet isn’t fasting in the traditional sense. We refer to it as a modified fasting program because, in this method, you break up your fasts between meals, meaning you still eat two although quite small meals during your biweekly fast days and won’t be completely abstaining from food.
In the 5:2 Diet, you still get to eat on your fasting days. You’ll simply restrict your daily caloric intake to either 500 calories (for women) or 600 calories(for men).
In essence, the 5:2 Diet actually promotes extreme caloric restrictions twice a week, not strict abstention of eating food and calorie-laden drinks. And the other five days of the week, you go about your usual eating routine. These sections take a closer look at the 5:2 Diet and examine the glycemic index, which is an important concept to better understand how the 5:2 Diet works.
Uncovering this diet’s characteristics
One of the perks of the 5:2 Diet is that you aren’t dieting most of the time, and the research has shown that this type of fasting style is as effective in weight loss as long-term calorie restriction. Unlike fasting on occasion, daily calorie restriction over the long term typically leaves its followers feeling deprived. As a result, they commonly fall off the wagon and don’t get back on again until they come across another fad diet that promises quick fat loss. With the 5:2 Diet, you eat as you normally eat five days a week. Twice a week, you greatly restrict your calories to just 500 (for women) or 600 calories(for men).
For example, say you ate your last meal at 8 p.m. on Sunday. The following morning you eat a small breakfast (really nothing more than a healthy snack; refer to the later section, “Figuring Out What You Can Eat” for what is appropriate to eat during your fast day meals), and then you have another small meal sometime that evening. When you wake up Tuesday morning, it’s back to business as usual. You return to your regular eating patterns, not to fast again until your second fast day that week.
For the calories that you do eat while on your modified fasting days, choose ones that won’t raise your blood sugar too much. The reason for this is twofold:
- Fasting can give your body a rest from having to pump out insulin and thus raising your blood sugar
- Any food you eat will have an effect on your blood sugar, so if you spike it too much too quickly, you’ll experience the dreaded blood sugar crash and may not be able to complete a successful
Because of variations in body weight, hormones, and other factors, women and men have different caloric limits on the 5:2 Diet fast days. Women are limited to 500 calories, whereas men are limited to 600 calories. We help you get started with these meals.
The 5:2 Diet, like other fasting methods, can help do the following:
- Activation of the body’s repair genes: When fasting, a process in the body, called autophagy, gets switched Autophagy means to self eat, so in this repair process the body begins to break down and dispose of old, tired cells, making way for new, healthy ones.
- Better moods: The 5:2 Diet can increase the production of a protein called brain-derived neurotrophic factor (BDNF). Studies have shown that increased levels of BDNF can positively affect the brain, and therefore mood, in much the way that sustained antidepressant medication
- Increased insulin sensitivity: The 5:2 Diet helps the body use insulin more effectively, meaning that you don’t need to produce as much insu- lin to get the same amount of work By using insulin more effec- tively, you place less stress on your pancreas, as well as head off the negative effects that too much insulin can cause, such as accelerating the aging process.
- Reduction of insulin-like growth factor (IGF-1) levels: IGF-1 is a hormone that humans The variances in levels present in children help determine growth and future height. However, over time, it’s beneficial for adults to have lower levels of IGF-1 because higher levels later in life are correlated with an increased risk of cancer, as well as premature aging
- Fasting periodically seems to decrease IGF-1 levels in adults, potentially reducing the likelihood of developing common diseases that are associated with age, such as diabetes and cancer. Thus, although it doesn’t guarantee immortality, fasting on occasion may give you a taste of the Fountain of Youth.
- Weight loss: The 5:2 Diet includes a decrease in body fat percentage and an increase in lean muscle
Grasping the importance of the glycemic index on the 5:2 Diet
Understanding the blood sugar’s effect on the body and the glycemic index of various foods will go a long way in ensuring the successful completion of a fast. The glycemic index (GI) is an indicator of how quickly your body’s blood sugar will rise after eating a particular food. Because carbohydrates affect blood sugar to a much greater effect than proteins or fats, the GI deals mostly with foods that are higher in carbs but don’t have a sizable protein or fat content (of course, there are exceptions to this rule). Blood sugar levels matter because the higher your blood sugar is, the more insulin your body produces. And when your insulin is turned on, your body simply can’t and won’t burn fat. So instead, it stores it, increasing your risk for weight gain, diabetes, metabolic syndrome, and even cancer.
The GI attributes a number that is affected not only by what types of carbohydrates you eat, but also by how much you eat. This is called the glycemic load (GL). You can derive the GL with this equation:
Glycemic Load (GL) = GI ´ carbohydrates (in grams) 100
In the GI, each food gets a score out of 100. Stick to food choices that have a score of less than 50 or a GL score less than 20 because foods with a low GI/ GL don’t cause such a rapid surge in blood sugar. They’re slower to digest and absorb in the body, thus helping to avoid a flood of insulin entering the bloodstream.
Furthermore, when talking about GI/GL, not all carbohydrates are created equal. It probably doesn’t come as a surprise to anyone that a pear has a considerably lower GI than, say, pancakes slathered in maple syrup. Some foods have GI and GL scores that you might not expect. For example, take dark chocolate. Fifty grams, or 1.8 ounces, of the bittersweet stuff has one of the lowest GI scores a mere 23. On the other hand, one ounce of breakfast rice cereal has a GI score of 89.
The GI is important when you’re fasting on the 5:2 Diet because the fact that higher GI/GL–scoring foods will encourage your body to release insulin and store fat; the inevitable blood sugar crash that comes after eating a high glycemic food will only make fasting that much more difficult. You’ll wind up with that uncomfortable empty feeling in your stomach and want to eat again, rather than enjoying longer levels of feeling full and satisfied if you choose foods that are lower on the GI/GL scale.
Fasting paired well with the Paleo Diet can help improve your results. You can’t go wrong trying to stick to Paleo friendly foods while on both your fast and nonfast days.
Only foods that have sizable carbohydrate levels are measured with the GI. That means that foods such as most nuts, eggs, and other protein- and fat-rich foods don’t have a GI or GL score, which also means that they won’t wreak havoc on your blood sugar levels.
Table 5-1 lists some Paleo friendly foods with low GI/GL scores that are good for your two fasting days each week on the 5:2 Diet. On your nonfasting days, you can still reach for these foods as a snack to keep your GI/GL levels low.
|Table 5-1||Fasting Day Fo||od Choices wit||h Low GI/GL Scores|
|Food||GI||GL||Portion Size (grams)|
When planning out your fasting day foods, be sure to check serving sizes. Because you’re only allowed 500 calories (for women) or 600 calories (for men) while following this diet, it can be all too easy to go over your allotted calories, if you don’t keep serving sizes in check. You can also search online for food calculators that can help you figure sizes of different foods.