Experts Rate Best and Worst Diet Fads of the Past Century, Endorsing ‘Old Reliable’ Balanced Eating

A Daily Mail survey of health experts ranking diet trends of the past 100 years found broad support for Mediterranean and DASH-style eating patterns and strong criticism of short-term cleanses and extreme low-carbohydrate regimens. The panel also identified a simple approach — a balanced, minimally processed diet paired with portion control and physical activity — as the most reliable strategy for long-term health.

The article noted that roughly 41 percent of adults in the United States are overweight or obese and that about one in five Americans report being on a diet at any given time. It traced the rise of modern dieting to the 19th century, citing William Banting’s 1863 pamphlet "Letter on Corpulence" as an early guide to weight loss, and described how dieting evolved into a major health and beauty phenomenon in the 20th century.

Experts who spoke to the Daily Mail ranked diet patterns on a roughly 0–10 scale. The Mediterranean diet received the highest marks for promoting long-term health. Nutritionists pointed to an evidence base that links the pattern — rich in fruits, vegetables, whole grains, legumes, olive oil and moderate fish and poultry intake — with lower risks of cardiovascular disease and cognitive decline. The PREDIMED study, published in the New England Journal of Medicine in 2013, found that participants randomized to a Mediterranean-style diet had about one-third lower rates of heart attack, stroke and cardiovascular death than those advised to follow a low-fat diet.

The DASH diet, developed from National Institutes of Health–supported research in the 1990s to lower blood pressure, also scored highly. The American Heart Association has endorsed DASH-type patterns for meeting its nutrition guidance and highlighted long-term associations with reduced coronary heart disease and stroke risk. Harvard researchers cited by the Daily Mail reported that people who adhered to DASH-like eating for decades had a reduced risk of coronary events compared with those who did not.

Weight Watchers, the commercial program founded in New York in 1963, was praised for its flexibility and social-support model. The program’s points-based system assigns values to foods according to nutrient content rather than strict calorie counting, and trials have shown modest but clinically meaningful short-term weight loss among participants. A BMJ trial involving hundreds of adults found greater weight loss at 12 weeks among Weight Watchers participants than among comparison groups, and systematic reviews have reported modest advantages at 12 months.

By contrast, several popular fads drew sharp criticism. Juice cleanses, which typically involve consuming only fruit and vegetable juices for several days to a week, were given some of the lowest ratings. Dermatologist Michele Green and fitness experts questioned the sustainability and nutrient adequacy of these regimens. The National Center for Complementary and Integrative Health warns that juice-only programs can cause electrolyte imbalances, headaches, fainting, weakness and dehydration and that the body’s liver and kidneys are effective at removing toxins without special diets.

The ketogenic diet, introduced in the 1920s as a treatment for epilepsy, also ranked poorly among some of the experts interviewed. While clinicians still use very-low-carbohydrate ketogenic regimens therapeutically for seizure control, critics say the diet’s restrictions can limit fiber-rich foods such as whole grains, legumes and many fruits, and can be high in saturated fat. The Dietitians Association of Australia and the American Heart Association have cautioned that long-term safety and efficacy for the general population remain uncertain and that benefits seen in short-term studies often dissipate over a year.

The South Beach Diet, developed by cardiologist Arthur Agatston in the mid-1990s and popularized by a best-selling book, was described as potentially effective in the short term but difficult to sustain. Its early phase restricts many carbohydrates and emphasizes lean protein and nonstarchy vegetables; later phases reintroduce whole grains and fruit in controlled amounts. Critics told Daily Mail they see the plan as reinforcing restrictive habits that may be hard to maintain across diverse cultural diets.

When asked which approach has stood the test of time, multiple experts emphasized principles rather than brands. Los Angeles-based pulmonologist and sleep medicine specialist Raj Dasgupta described the "one approach that never goes out of style" as eating a variety of minimally processed foods, watching portions and staying physically active. "It's not flashy, but it's reliable and backed by decades of solid research," he said. Dermatologist Green echoed that moderation and not eliminating entire food groups tends to support adherence and a healthier relationship with food. Fitness trainer Natalie Alex predicted a future shift toward personalized nutrition tailored to lifestyle and health needs rather than rigid, universal rules.

The Daily Mail roundup places popular and historical diets in a broader context of changing tastes, medical uses and cultural pressures. It highlights both randomized trials and long-term observational studies that support dietary patterns emphasizing plant foods, healthy fats and whole grains, while warning of the limited evidence and potential harms of extreme short-term cleanses and highly restrictive regimens for the general public.

Experts contacted for the piece encouraged people seeking weight loss or health improvements to consult health professionals for individualized guidance and to consider sustainability, nutrient adequacy and the potential long-term cardiovascular effects of any dietary change. They noted that while new pharmacologic tools for weight management have emerged in recent years, foundational principles of diet quality, portion control and regular movement remain central to public health recommendations.