Here is a summary and review of the 5:2 diet from MD Anderson's dietitians' information:
What is the 5:2 Diet?
Eat normally for 5 days of the week.
Eat very low-calorie meals (500–600 calories) on the other 2 non-consecutive days.
It's sometimes called an intermittent fasting regimen, but technically not a true fast, as it does contain food.
How Does It Work?
It works as a calorie-restricted diet.
Some people find it easier to follow because you only restrict yourself 2 days a week.
Like any diet, the quality of the diet, medical history, and genetics all affect the outcome. Experts' Concerns extremely stringent on days of fasting, which some people may not be able to maintain.
Does not always guarantee sufficient nourishment, particularly on days when fasting is observed. can have detrimental effects on bowel regularity, the gut microbiota, and general health if not properly balanced.
What Do MD Anderson Dietitians Recommend?
They do not usually suggest the 5:2 diet.
Rather, they suggest a regular, balanced diet based on:
Whole grains
Vegetables and fruits
Lean protein
Plant-based meals
Final Takeaway:
Although the 5:2 diet might be effective in weight loss for some, the long-term sustainability and nutritional balance should be considered. A steady, whole-food-based diet is safer and more advantageous for overall health.
The 5:2 diet has been referred to as a type of intermittent fasting. Is that true?
No. Technically, fasting is when you completely avoid eating for a period of time. But sometimes people inaccurately refer to it as that because the amount of food you consume on those two days is not sufficient to satisfy your body's minimum requirements.
Does having plain water constitute breaking a fast?
No. But all drinks with calories do, so lattes, smoothies and sports drinks sweetened with fruit juice, as well as sweetened fruit juice-flavored waters, are all out.
How does the 5:2 diet theoretically work?
The 5:2 diet is simply another calorie-restricted diet. And it's very restricting on those two days. So, I wouldn't personally advise it.
But some people find it easier to eat normally on five days and then cut back on only two. They feel like if they can manage their calorie intake and make it through those, then they’re good.
How long does it take for the 5:2 diet to start working?
That will all depend on the person: their history, genes, and what they usually eat. No two people lose weight in exactly the same fashion or at exactly the same pace. So in that sense, at least, it's not really any different from any other diet that limits calories.
What's a normal day like during the 5:2 diet?
Once again, this is not what we would suggest. But if you're absolutely bent on attempting it, just remember that "eating normally" does not necessarily imply that you can gorge and consume anything desire during those five days.
You still need to shoot for a healthy, balanced diet with loads of whole grains, vegetables and fruits and lean protein.
On the two "fasting" days, it's best to stick to consuming really nutrient-dense foods, such as leafy greens, whole grains and lean meats, so that you're getting as many nutrients as you can. Whole foods and lean proteins will also keep you full for longer, so you can get through those long "fasting" days.
One of the downsides to this kind of diet is that it doesn't consider the nutritional aspect of things. Sure, it reduces calories and can eventually be good for weight loss, but it's really difficult to remain healthy when you have less chance to consume the things your body needs to flourish. And, that can have a negative effect on your gut microbiome and bowel regularity, to name a few.