Fast Diet Expert Reviews

Star ratings reflect scores of 1 to 5 assigned to the DASH diet in eight categories by nutritionists, specialists in diabetes and heart disease, and other diet experts on a ratings panel assembled by U.S. News. (See our Best Diets methodology.)  The experts expressed concern about the Fast Diet, particularly that its lack of guidance could result in poor food choices and overeating on non-fasting days. One expert said the diet undermines the physiological importance of a regular eating schedule. Another called the diet “just a gimmick,” with “little science to support” it – “but a new twist on the need to decrease calorie intake.” 

Star ratings reflect scores of 1 to 5 assigned to the Fast Diet in seven categories by nutritionists, specialists in diabetes and heart disease, and other diet experts on a ratings panel assembled by U.S. News. (See our Best Diets methodology.)  The experts expressed concern about the Fast Diet, particularly that its lack of guidance could result in poor food choices and overeating on non-fasting days. One expert said the diet undermines the physiological importance of a regular eating schedule. Another called the diet “just a gimmick,” with “little science to support” it – “but a new twist on the need to decrease calorie intake.” 

Overall Score 2.5

Short-Term Weight Loss

18 Ratings
5 Star
(1)
4 Star
(4)
3 Star
(12)
2 Star
(1)
1 Star
(0)

Score 3.3

The Fast Diet earned the average score of 3.3 stars in this area, indicating that it might help dieters with short-term weight loss – or it may not. While reducing overall calorie intake, as the diet prescribes, will bring about weight loss, experts wondered whether dieters would compensate on non-fasting days by overindulging. However, one expert said it could be a useful new way to motivate dieters who have grown discouraged with their weight-loss efforts.

The Fast Diet earned the average score of 3.3 stars in this area, indicating that it might help dieters with short-term weight loss – or it may not. While reducing overall calorie intake, as the diet prescribes, will bring about weight loss, experts wondered whether dieters would compensate on non-fasting days by overindulging. However, one expert said it could be a useful new way to motivate dieters who have grown discouraged with their weight-loss efforts.

Long-Term Weight Loss

18 Ratings
5 Star
(1)
4 Star
(0)
3 Star
(6)
2 Star
(8)
1 Star
(3)

Score 2.4

The Fast Diet earned less than 2.5 stars for long-term weight loss, a below-average score in this realm, just below the macrobiotic, Atkins and Eco-Atkins diets. Experts cited a lack of evidence to support long-term weight loss and questioned the feasibility of sticking with the program for an extended period. “The goal is to lose weight – and change lifestyle habits,” said one expert. “This diet does not do either.” 

The Fast Diet earned less than 2.5 stars for long-term weight loss, a below-average score in this realm, just below the macrobiotic, Atkins and Eco-Atkins diets. Experts cited a lack of evidence to support long-term weight loss and questioned the feasibility of sticking with the program for an extended period. “The goal is to lose weight – and change lifestyle habits,” said one expert. “This diet does not do either.”

Easy to Follow

18 Ratings
5 Star
(0)
4 Star
(2)
3 Star
(5)
2 Star
(11)
1 Star
(0)

Score 2.5

The Fast Diet received an average score of 2.5 stars, with experts noting their concern about its long-term sustainability and lack of guidance. Those who suffer from severe short-term calorie restriction might find it hard to follow. However, the diet could work for extremely busy people and those struggling to cut calories on a daily basis, said one expert, who called it “relatively easy to follow compared to the diets that required structured meal choices or significant food preparation.”  

The Fast Diet received an average score of 2.5 stars, with experts noting their concern about its long-term sustainability and lack of guidance. Those who suffer from severe short-term calorie restriction might find it hard to follow. However, the diet could work for extremely busy people and those struggling to cut calories on a daily basis, said one expert, who called it “relatively easy to follow compared to the diets that required structured meal choices or significant food preparation.”

Nutrition

17 Ratings
5 Star
(0)
4 Star
(1)
3 Star
(4)
2 Star
(9)
1 Star
(3)

Score 2.2

With just 2.2 stars for nutritional completeness, the Fast Diet scored near the bottom of the rankings in this area, reflecting experts’ common concerns that the diet lacks sufficient guidance for the five non-fasting days. Rather than promote a healthy eating pattern, this diet allows followers to keep up or even develop unhealthy habits five days a week, they said. On the two fasting days, a state of hunger may affect mood, work performance and personal interactions. Also, the sample menu indicated low values of certain nutrients such as calcium, potassium and fiber, one expert noted.

Safety

16 Ratings
5 Star
(1)
4 Star
(1)
3 Star
(5)
2 Star
(9)
1 Star
(0)

Score 2.6

Experts registered significant concern about the safety of the Fast Diet. In handing out an average of 2.6 stars, the diet landed near the bottom of the batch, outranking only the Paleo, Dukan, Atkins and raw food diets. The diet is not considered appropriate for anyone who becomes light-headed without food or for diabetics, who would be at risk of low blood sugar. One expert, noting the lack of attention to the “quality of diet” on the non-fasting days, called the program “a potential invitation to eating disorders.” It was also advised that dieters should drink plenty of water on the fasting days.

For Diabetes

18 Ratings
5 Star
(1)
4 Star
(0)
3 Star
(8)
2 Star
(6)
1 Star
(3)

Score 2.5

The Fast Diet is not recommended for diabetics or prediabetics because the drop in caloric intake could put them at risk for hypoglycemia, or low blood sugar. Also, diabetes medication would require adjustment on this diet, according to one expert. Earning just 2.5 stars in this category, the Fast Diet scored near the bottom of the rankings as a program to help prevent or control diabetes.

For Heart Health

18 Ratings
5 Star
(1)
4 Star
(0)
3 Star
(9)
2 Star
(6)
1 Star
(2)

Score 2.6

As a program to prevent or control heart disease, the Fast Diet earned below-average marks of 2.6 stars, just below the Abs and Medifast diets. However, if you’re using calories wisely on fast days, you’ll likely consume foods that are high in fiber and low in saturated fat such as fruits and veggies, which help to promote heart health. 



Last updated by Laura McMullen | January 03, 2014

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