The 5:2 Diet Review

The 5:2 diet took off in the United Kingdom after a 2012 television documentary proclaimed the benefits of the eating plan. The diet quickly spread through Europe and the United States as people began shedding a lot of weight quickly.

The diet calls for intermittent fasting (IF). You choose two nonconsecutive days a week to severely restrict your calorie intake, and the other five days you eat what you want. This form of alternate-day fasting is how the diet got its name: 5 days off, 2 days on.

Numerous celebrities and talk show hosts, such as Hugh Jackman, Jimmy Kimmel, and Benedict Cumberbatch, all state that this eating plan not only helped them shed excess weight, but allowed them to still work out and build muscle.

For the 5:2 Diet you choose two nonconsecutive days a week to severely restrict your calorie intake. Men may eat 600 calories and women may eat 500 calories.

The Diet Plan

To follow the 5:2 diet, choose two nonconsecutive days each week that you can severely limit your calorie intake. Many people choose weekdays when they don't have plans with friends or family that might make fasting more difficult.

On these two "Fast Days", men may eat 600 calories and women may eat 500 calories. You may eat what you like. Typically, dieters choose a simple but filling breakfast, such as ham and eggs, and a protein-rich lunch or dinner. To keep your calories under the daily limit, you must restrict the portion size of your meals.

On the five non-fasting days of the week, called "Feast Days", you may eat whatever you like. You are not required to count calories. Although it may seem like dieters would binge on these Feast Days, some researchers have found that the opposite happens.

Many dieters actually eat fewer and healthier foods because they take extra time to choose and appreciate what they eat.

Each dieter has his or her own tricks for warding off hunger pangs on Fast Days. Some recommend drinking hot tea or munching on low-calorie snacks such as rice crackers or baby carrots. If you try this diet, you may have to experiment to find out what works for you.

What Does Science Say?

While fasting dates back thousands of years, recent scientific research backs up claims that this type of eating plan not only helps the body to maintain a stable weight, but can prevent disease as well.

The University of Southern California found in one study that mice who fasted 2 to 5 days each month had reduced biomarkers for cancer, heart disease, and diabetes.

Another study conducted at The Longevity Institute found that both mice and humans who practiced fasting had a lower risk of cancer and helped them maintain a normal body weight.

Lastly, in studies performed at the University of Illinois at Chicago found that, in a 10 week trial, people lost an average of 13 pounds, along with vastly lower blood pressure, insulin, triglycerides, and LDL (bad) cholesterol.

Other Benefits to Intermittent Fasting

Generally speaking, intermittent fasting has been found to have impressive health benefits, in addition to losing weight or maintaining a healthy weight.

Most people find that this type of eating plan is easier to follow than a daily calorie restricted diet. In addition, studies have found that those who followed an intermittent fasting program, when compared to a low calorie diet plan:

  • Had 40% lower leptin levels
  • Reduced blood triglycerides by 20 percent
  • Reduced fat mass by almost 4 kilos, but had no change in muscle mass
  • Reduced their body weight by more than 5 kilos
  • Had lower levels of inflammation
  • And had increased LDL particle size (this is a positive change)

Many people also state that they are less hungry and less irritable on an intermittent fasting plan than a calorie restricted plan. This might be because there are virtually no cravings associated with this plan.

As if this were not enough, followers of intermittent fasting have improved skin health, improved joint health (due to lower inflammation levels), eased asthma symptoms, and a vast increase in energy levels.

Helpful Tips:

While many people find this diet is easy to follow, there are a few tips that will help you, especially in the beginning.

  1. Use a calorie counting book or app to help track calories on your fast days
  2. Avoid restaurants or fast food joints on fasting days
  3. Increase your motivation by telling supportive friends and family
  4. If you fail to “fast” on your planned day, don’t sweat it! Simply choose another day or try again the next week.
  5. On fast days, think FLAVOR! Sip tangy teas or fruit infused waters
  6. Keep yourself busy and distracted on fasting days
  7. Remember that protein will make you feel more satisfied and full longer than carbs
  8. Pre-plan meals on your fasting days and have an emergency stash of fresh, low cal veggies on hand just in case!
  9. Supplements can help to dull your appetite until your body adjusts to this change. Try chromium. L-glutamine, or NAC.
  10. Aim for a variety of textures and flavours during your fast. Think popcorn, soup, and salads

Sample Plan for Fasting Days

Men (600 Calories)
  • Breakfast: Black coffee, two scrambled eggs
  • Black coffee, water, flavoured teas during the day
  • Dinner: 8 ounces of steamed fish and 8 ounces of steamed mixed vegetables
  • Evening snack: 2 cups of air popped popcorn with garlic salt
Women (500 calories)

Women can have the same as above, but cut the meat and vegetables back to 4 ounces.

Pros & Cons

Pros

This diet allows you to continue eating the things you love. If you're someone who loves to eat at restaurants or go out with friends, the 5:2 diet allows you to do that all but two days of the week.

Many people also like that this diet doesn’t require any special shopping or preparation. On Fast Days, you may simply eat what you already have – just in moderation.

Cons

For people with some medical conditions, such as blood sugar conditions like Type 1 diabetes, this diet may not be the best option. Additionally, if you struggle with binge eating, then you may not see the weight loss that many people experience. Some people have reported getting headaches on Fast Days, likely due to diet changes and drops in blood sugar. Others have reported insomnia, anxiety, and irritability.

Verdict

The jury is still out on whether the 5:2 diet is effective and safe. Many people have lost a lot of weight using the diet, but major research studies have yet to conclude that the diet works for most people.

For those who struggle to fit other weight loss diets into their lifestyle, the 5:2 diet may be worth trying. However, because of concerns about how fasting may affect blood sugar, you should check with your doctor before beginning this diet.