What Are the Health Risks of Fad Diets?

As obesity rates rise in the United States, so do fad diets and their health risks.

“Quick-fix diets promote a magic bullet for fast and dramatic weight loss,” said Richard Doscher, RD, CDN, Director of Nutrition & Food Services at Good Samaritan University Hospital. “They fail to live up to expectations, and most importantly, can negatively impact your health.”

How can I spot a fad diet?

Fad diet eating plans promote fast weight loss with little to no effort. You can recognize a fad diet because they often:

Exaggerate how much weight you can lose
Focus on “good” vs. “bad” foods
Have rigid, difficult-to-manage rules
Promise a quick fix for weight loss
Rely heavily on celebrity endorsements and testimonials
Restrict or eliminate certain foods or food groups
Severely restrict calories
Suggest certain foods that can change your body chemistry

“If something sounds too good to be true, it usually is,” said Doscher.

What are the health risks of fad diets?

Fad diets may not seem harmful initially, but they pose health risks. Although someone may lose weight quickly in the short term, the results from these diets do not last.

Once a person stops following the fad diet, the weight typically returns as quickly as lost. Weight cycling—repeatedly losing weight and gaining it back—can increase the risk of health conditions such as heart disease and high blood pressure.

Health risks of fad diets include:

Decreased physical activity. A balanced diet and exercise will help you maintain a healthy weight. Fad diets—excessively restrictive ones —often leave you feeling too tired to exercise. Many also do not emphasize the importance of exercise for weight loss and management.
Disordered eating. Some fad diets treat eating like a disorder, which can affect your relationship with food even after you stop following the diet. Disordered eating can also lead to binge eating, purging or skipping meals.
Metabolic imbalance. Your metabolism regulates how your body converts food into energy. Fad diets can slow your metabolism, so your body does not turn food into energy as quickly as it used to, or make it harder to lose weight in the future.
Nutritional deficits. Your body needs different nutrients to work correctly. Cutting out certain food groups and the nutrients they provide can negatively impact your health over time. If a fad diet cuts out certain foods, you may experience digestive issues, fatigue or general weakness.
Poor mental health. Fad diets can lead to poor mental health. Their restrictive nature makes them difficult to stick to, leaving no room for mistakes. You may feel guilty or stressed if you cannot follow the diet. Fad diets can also lead to an unhealthy obsession with eating, causing anxiety over food choices.

How can I lose weight safely?

“A well-balanced diet, regular exercise and getting enough sleep can get you started,” said Doscher.

A healthy eating plan includes:

Beans, eggs and nuts
Fruits, vegetables, whole grains and fat-free or low-fat dairy
Lean meats, poultry and fish
Limited amounts of added sugar, saturated and trans fats and sodium

Portion control is also essential for healthy weight loss. Reducing your calories by 500 to 750 calories per day can help. A caloric intake of 1,200 to 1,500 can promote safe weight loss for women. Men should eat 1,500 to 1,800 calories per day.

Regular exercise can help you lose weight or maintain a healthy weight. Moderate to vigorous exercise is best—you want to get your heart rate up. Aim for 150 minutes of moderate or 75 minutes of vigorous exercise per week. Regular exercise can also improve your sleep quality, vital for weight loss.

“Fad diets do not teach long-term habits that are good for your physical and mental health,” said Doscher. “Talk to your primary care physician, who can recommend you to a dietitian who will help you create a healthy eating plan and reach your health goals.”