Debunking the 5:2 Diet

Fasting or severely restricting calories to lose weight isn’t a new idea. However, it has gained attention again in the form of the 5:2 diet. The 5:2 diet is frequently presented as a great diet option for people who love food and don’t want to make extreme changes to their lives. On the diet, individuals are asked to limit their calorie intake (500 calories for women and 600 calories for men) on two non-consecutive days of the week. For the rest of the week, people can eat as they normally do; no restrictions necessary.

Can a diet that encourages people to limit intake, but not add any exercise, or otherwise change their eating habits be truly effective? Experts aren’t convinced. “A feast or famine approach promotes binge-eating and game-playing, and that leads to weight gain.” said Registered Dietitian Mary Hartley. The 5:2 diet may help people lose weight in the short-term, but isn’t likely to be effective over a long period of time, no matter what its supporters think.

Proponents of the diet feel that research done on animals proves intermittent fasting is an effective weight loss tool and has other healthy impacts on the body. Research shown in the documentary “Horizon: Eat, Fast and Live Longer” appeared to prove that intermittent fasting helped mice live longer, healthier and lighter lives. “Intermittent fasting is gaining some attention in the world of rat research,” Hartley said. “The process seems to help rats lose weight more easily, which makes sense because if calories are cut for two days out of seven, overall calorie intake will be less than if fasting did not occur.” Be that as it may, intermittent fasting in any form is not the way to go for a total lifestyle change.

“Any bizarre practice with rigid guidelines that you have to read in a book takes you away from connecting with your body, and that is a problem,” Hartley said. The most effective diet is one that encompasses a lifestyle change, meaning exercise and eating habits. Changing eating habits twice a week isn’t enough to create a sustainable healthy life. “The body prefers nutrient-rich, wholesome foods eaten in the right amount for you with consistency from day to day,” Hartley said. “Fasting is not more helpful than watching what you eat from day to day and I wouldn’t recommend it.”


The 411 on Fasting Diets

Should You Try Intermittent Fasting?

The Dangers of Juice Fasting and Quick Weight Loss


Eternal Gardener
Eternal G4 years ago


Val M.
Val M4 years ago


june t.
reft h4 years ago

never heard of it before, thanks

Manuela C.
Manuela C4 years ago


Fred Hoekstra
Fred Hoekstra4 years ago

Thank you Brandi, for Sharing this!

Kirsten Vines
Past Member 4 years ago

Sounds like another fad to me!
Just keep it low everyday!
I eat less than 1100 calories per day, and exercise off between 500-700 daily. It takes a little getting used to, but if you eat the right foods (and they're all nutritious) you never get hungry, and the more you get into exercise the more energetic you actually end up feeling.

Louisa Duffy
Louisa Duffy4 years ago

I completely disagree with the comments Hartley made. I have been of the 5-2 for 4 1/2 months now and am steadly loosing weight, but the best part is that I feel fantastic, have more energy than when I was in my 20's, my blood sugars have finally leveled out, I sleep like a baby, have less pain, get through a full 9 hr day at work with ease, can consentrate and remember things I was having trouble with before and I finally have energy to excersise if I choose to do so. Fasting is not that difficult and it has soo many benifits I would recomend it to anyone and when I mentioned it to my doctor he said 'fantastic, keep going'. I have always had a fresh food diet so that has not changed, infact I have changed very little in my diet except when I eat.

Kay Martin
Kay M4 years ago

Thank you for the article, and all the comments from the care 2 members, I have tried all of the diets out there, the one I liked the best was the doctor supervised liquid, I stayed on that for one solid year, but The minute he took me off it, I gained back all and more of my weight, because I had never learned how to judge carbs.protein,fruits,and veggies. All I did was mix a pack of powder with a liquid and drink, did not have to think or plan anything, after years of up and down, I have finally found something to stick to that is working well for me, and that my new doctor likes. Do what is best for your own personal health, do not follow the pack on any new diets out talk to your doctor first always.....period

Katie K.
Katie K4 years ago

Did something similar before a vacation and packed all the clothes and swimwear that I look best in. Needless to say, after the 2nd day I couldn't get in a single thing comfortably that I had packed since we ate and drank like kings and queens. I sneezed in a restaurant and the button on my skirt went flying. That's the problem with these diets, you have to stay with it our you go immediately back to where you began.

Anna Undebeck
Anna Undebeck4 years ago

Thanks for sharing.