1. Juice Only Diet

A juice-only diet will cause you to lose water weight and muscle mass, but not fat. Once you start eating solid food again, the pounds will come piling right back. A juice diet lacks protein, calcium, and fiber, so it deprives your body of important vitamins, minerals, and nutrients it needs to function properly.

2. Skipping Meals

Skipping meals might be an easy way to reduce calories, but doing so may actually result in weight gain. In a study published in the Journal of Nutritional Biochemistry, skipping meals is linked to abdominal weight gain. It may cause larger fluctuations in insulin and glucose, and lead to more fat gain.

3. Gluten-free Diet

There’s no scientific evidence that shows a gluten-free diet will help you lose weight. It might actually cause weight gain if you regularly eat gluten-free packaged foods like breads or muffins. Manufacturers commonly add additional fat, sodium, and sugar to compensate for the lack in flavor and the texture of gluten. So they are often higher in calories.

4. Fat-free Diet

Cutting all fat from your diet will not only leave food tasteless, but could also be unhealthy for you. Not eating enough fat has been associated with hunger, dry skin, and extreme mental fatigue. A study of 135,000 adults published in the Lancet found that those who cut back on fats had shorter lives than those with a higher dietary fat intake.

5. Cutting Out Food Groups

It may seem that cutting out carbs or sugar altogether would lead to weight loss, but doing so long-term may compromise your health. Each food group consists of essential nutrients that the body needs for normal and healthy function. Eliminating entire food groups may put your body at risk for a number of nutritional deficiencies, and is not sustainable in the long run.

6. Drinking Ice Water

While it is true that drinking water that is cold will burn more calories than drinking water at room temperature, given that the body will work to maintain its core temperature, but the number of calories burned is negligible, only about 8 calories, according to experts at the University of Washington. Drinking ice cold water would not be effective in achieving weight loss.

7. Drinking Diet Soda

It may seem sensible to switch from sugary sodas to diet sodas to help in weight loss, but there are some health risks involved. A number of studies have associated diet soda with weight gain, diabetes, heart problems, dementia, and other health issues. A study published in the journal Stroke showed that drinking two or more diet sodas per day is linked to a higher risk of stroke and heart disease.

8. Weight Loss Shakes

Weight loss shakes may seem like an easy way to lose a few pounds, but they are not a long-term solution. Although they contain some essential nutrients, they cannot replace a healthy diet of whole foods with the necessary vitamins, minerals, fiber, antioxidants, and enzymes. They are not sustainable long-term, and going back to old eating habits will likely cause weight regain.

9. Too Much Protein

High-protein diets may help in weight loss, but only for the short-term. The excess protein consumed is usually stored as fat, so eating too much protein could actually result in weight gain. Also, several studies show that eating too much protein is associated with an increased risk in heart disease, cancer, kidney disease, and other health issues.

10. Cutting Calories

According to conventional wisdom, you need to cut back on calories in order to lose weight. But cutting calories will cause your body to go into starvation mode, which slows down the metabolism, burns fewer calories, and breaks down muscle to use for energy. A review of over 30 long-term dieting studies published in American Psychologist showed that more than two-thirds regained more weight than they lost.

11. Sugar-free Foods

Just because a package is labeled sugar-free does not mean that they are healthy or low-calorie. Sugar-free foods often compensate for the lack of sugar with higher amounts of fat and carbohydrates. An analysis of clinical trials and studies published in the Canadian Medical Association Journal found that artificial sweeteners were associated with obesity, high blood pressure, type 2 diabets, and heart problems.

12. Overeating Healthy Foods

While eating healthy foods in right amounts will help in maintaining a healthy weight and overall well-being, eating too much of them will keep you from achieving your weight loss goals. While healthy foods such as salmon, avocados, and quinoa are full of protein, fats and fiber, they are also high-calorie foods. So eating too much of a good thing would not help your waistline.