Does your diet have you dreaming of drowning in ice cream? It may be time to consider The 5:2 Fast Diet. The claims are lofty: namely, that you can lose weight, live longer and gain a ton of health benefits, all without eliminating any type of food. Sound too good to be true? Let’s examine the facts.

The concept behind this globally trending diet plan is simple. Indulge in whatever foods you love five days a week, and put your body on starvation mode for the remaining two, non-consecutive days. It’s not literal starvation, but rather consuming 25% of one’s target calorie consumption per day. That works out to roughly 500 calories per “fast” day (2,000 calories per “feast” day) for women and 600 calories per “fast” day (2,400 calories per “feast” day) for men.

Spring Green 5:2 Diet Recipe: Moroccan Roasted Vegetable Salad with Feta Cheese (200 calories)

Spring Green 5:2 Diet Recipe Moroccan Roasted Vegetable Salad with Feta Cheese (200 calories) – Photo by: flickr/Karen Booth under license CC BY-ND 2.0 

While the “eat a lot today, I’ll cut back tomorrow” concept has been around for generations (hello, Black Friday), it formally became what’s now called The 5:2 Diet in 2012. In a BBC special called “Eat, Fast and Live Longer,” British physician Michael Mosley declared this regimented approach to food could add years to one’s life, while also reducing the risk of heart attack, cancer, stroke and pre-diabetic conditions. A short time later, another BBC’er named Kate Harrison took the idea and ran with it, publishing a bestseller called The 5:2 Diet Book, which suggests dedicated followers can expect to lose around a pound per week.

Today, the diet plan–also known as The Fast Diet or “going 5 and 2”–is a growing phenomenon throughout much of Europe and Australia with a small, but growing following in the United States. The plan is so popular in the UK that dieters there have the option of ordering appropriately portioned meals delivered to their doors from the “Fast Diet Kitchen”. Proponents of 5:2 cite the simplicity of the diet and the lack of restrictions as major factors in their decision to stick with it.

Said one 5:2ing New Yorker, “I love that I don’t have to think about it. I used to obsess over every calorie. Now, as long as I stick with just a bowl of soup for lunch and dinner on Mondays and Thursdays, I know I’m good. And it’s easy to stay motivated knowing I can eat whatever I want the next day.”

ice cream crepe

Photo by: flickr/Dennis Hamilton under license CC BY 2.0

Of course, as with all fast diets, there are drawbacks. One criticism is that 5:2 is more of a lifestyle choice than a conventional diet, as gaining weight is common when people go off the plan. It’s also not ideal for competitive athletes or anyone who is extremely physically active, as the number of calories consumed must remain the same regardless of calories burned. Those with special nutritional needs, including women who are pregnant or breastfeeding, teens and children are advised by Harrison to avoid the diet all together.

While many experts debate the merits of going 5 and 2, there is some clinical and anthropological evidence to suggest intermittent fasting has health benefits beyond weight loss. Bottom line: As with any diet, nutrition should trump calories. If you do opt to restrict yourself to 500 or 600 calories per day, make them count! Fill up on dark leafy greens and legumes, whole grains and lean protein. Before you decide whether The 5:2 Diet is right for you, consult your doctor.