Our verdict: The diets on this page share common problems - they're nutritionally incomplete, unsustainable long-term, and often based on pseudoscience. We explain what the research actually shows so you can make informed decisions.
Every few months, a new diet promises to be "the one." Within weeks, most people have abandoned it. This isn't a failure of willpower - it's usually a failure of the diet itself.
The diet industry is worth over £2 billion in the UK alone. Much of that money is spent on approaches that research shows don't work long-term. Understanding why certain diets fail can save you time, money, and the psychological toll of repeated "failures" that were never your fault.
How We Identify Fad Diets
Red flags that suggest a diet is more marketing than science:
- Promises rapid results - More than 1-2 lbs per week is usually water or muscle, not fat
- Eliminates entire food groups - Without clear medical reason
- Requires special products - Supplements, shakes, or branded foods
- Based on pseudoscience - "Detox", "alkaline", "cleanse" with no mechanism
- Can't be maintained indefinitely - If you can't eat this way forever, results won't last
- Relies on testimonials - Instead of peer-reviewed research
The Diets
We analyse each diet based on peer-reviewed research, asking: does this support long-term health, or is it just another cycle of restriction and regain?
Juice Cleanses
"Detox" your body with juice. Spoiler: your liver already does that.
The Military Diet
Lose 10lbs in a week with ice cream and hot dogs. Yes, really.
The Alkaline Diet
Change your body's pH with food. Based on a fundamental misunderstanding of biology.
The Dukan Diet
Four-phase protein-heavy plan. Popular in France, criticised by nutritionists.
The Cabbage Soup Diet
Seven days of soup. A 1980s classic that somehow persists.
The Egg Diet
Eggs at every meal for rapid weight loss. Nutritionally limiting.
The OMAD Diet
One Meal A Day. Extreme fasting with real risks for most people.
The Whole30 Diet
30 days of elimination. Useful diagnostic tool or unnecessarily restrictive?
The Blood Type Diet
Eat for your blood type. Sounds personalised, but research says otherwise.
The Sirtfood Diet
Red wine and dark chocolate. Made famous by Adele, but is it safe?
The Raw Food Diet
Nothing cooked above 48°C. Based on enzyme myths and nutritional misconceptions.
Why Most Diets Fail
Research consistently shows that 80-95% of dieters regain lost weight within 1-5 years. This isn't because people lack willpower - it's because most diets are designed to fail:
- Too restrictive - Eliminating entire food groups creates cravings and social difficulties
- Metabolic adaptation - Your body fights back against rapid weight loss by slowing metabolism
- Psychological backlash - Restriction leads to bingeing, creating a harmful cycle
- Not sustainable - If you can't eat this way forever, the results won't last
What actually works: Long-term studies show that sustainable weight management comes from moderate changes you can maintain indefinitely - not dramatic restrictions you abandon after weeks. More vegetables, adequate protein, less ultra-processed food, regular movement. Boring, but effective.
Looking for Evidence-Based Diets? →
We also cover diets with real research behind them - Mediterranean, keto, intermittent fasting, and more. See what actually works for long-term health.
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