Fad diets have always been around, and each of them claims to offer a fast solution for losing weight and improving health. Surprisingly, some of them have even been touted by health practitioners as safe – but the truth has always been revealed over the years.

Health practitioners will often give their patients the mistaken impression that losing weight happens with only modest diet changes based on counting calories. For example, telling someone that if they cut out two cans of soda daily, they will lose 30 pounds in a year is untrue. The soda is 300 calories, and to lose a pound of fat, 3500 calories have to be expended.

This type of old weight loss guideline is fatally flawed because what’s not considered is the decreasing metabolism and declining energy expenditure with weight loss. It also doesn’t consider the impact of hormones, such as insulin resistance, on the weight loss process. Thus, a diet that is based on this method could be considered a fad.

And just because someone loses weight on a diet doesn’t mean that they’ll keep it off. Diets that emphasize fasting over extended periods of time are a prime example. During extended fasts, the metabolic rate drops to accommodate the fasting. When the person goes back to eating, the metabolic rate increases, but it does not meet the dietary intake of calories. Then the person gains weight back.

The key to weight loss via diet appears to be the macros. Shifting macros can create weight changes fast. Eat a high-carb diet, and you’ll gain weight by increasing insulin levels, which drive fat accumulation. A low-carb diet can result in weight loss over the short term. A high protein diet may also offer benefits for maintaining weight loss, especially if the foods consumed have a low glycemic index. Eat a keto diet, and it favors the burning of fat because of the limiting of carbohydrates, which are usually used for energy.

What makes a fad diet a fad, according to nutrition experts, is the restriction of certain food groups or nutrients from a diet. However, the whole field of diet therapy is based on therapeutic diets that do exactly this – restrict certain food groups or nutrients. And in many cases, there’s no accommodation made for the lack of nutrients in those food groups with supplements, giving the person a lesser quality of life in the long run.

With this in mind, let’s look at 10 fad diets throughout history and evaluate them.

• The Tapeworm Diet from the 1830s to 1900

Of all fad diets, this one was the oddest of all. It involved ingesting beef tapeworm cysts or eggs in the form of a pill. The idea was that the tapeworms would grow inside the GI tract and then absorb food so the person wouldn’t have to count those calories. Advertisements told potential clients that the tapeworms were sanitized.
Tapeworms cause anemia and malnutrition, and many unpleasant symptoms during the person’s decline of health. Although they didn’t restrict food at all, they put their clients in harm’s way.

• The Grapefruit Diet of the 1930s

This diet didn’t restrict foods at all, either. It added grapefruit or grapefruit juice with every meal. The idea was that the enzymes in the grapefruit helped burn fat.

On a good note, adding extra grapefruit to the diet did add extra vitamin C and a little fiber, but neither of these would affect weight loss. If grapefruit juice had been consumed, that juice might not have the enzymes claimed to have; when the juice had been heated, the enzymes would have been killed. Grapefruit, however, is a low-glycemic food, and weight loss may have resulted from preventing large surges in blood sugar that usually pack on the pounds.

• The Master Cleanse of the 1940s

The Master Cleanse is a mixture of lemon juice, maple syrup, cayenne pepper, salt, and water. They would drink anywhere from 10 to 40 days, and it is considered a liquid fast. No solid food is eaten at all. Laxative teas are taken during this time. Essentially, this diet consists of 40 to 60 grams of carbohydrates daily, with about 80-240 calories.

The premise is that this helps the body detoxify itself. In 2016, a study in the Journal of Ayurveda Integrative Medicine found that short-term lemon honey juice fasting may be useful for weight loss and can also lower high triglyceride levels. The caloric restriction was found to also offer lower levels of C-Reactive Protein, tied with inflammation in the body in another study. High levels of inflammation are found in those who are obese.

• The Cabbage Soup Diet of the 1950s

This diet involved consuming large quantities of cabbage soup and a limited selection of other foods for a week or more. There’s very little protein, fat, or carbohydrates in this diet. However, a diet rich in sulforaphane found in cabbage can help facilitate the body’s detoxification pathways and also will lower sulfate-reducing bacteria (gas-forming bacteria), according to a 2017 study.

Although there are definitely different flora strains in the gut of those who are obese compared to those who are skinny, at this time, we don’t know if this lowering of sulfate-reducing bacteria is beneficial to those who want to lose weight.
There haven’t been any studies on this diet, but most likely, weight loss is due to the diet being very low in calories.

• The HCG Diet in the 1950s and resurgence in the 2000s

This diet involved taking Human Chorionic Gonadotropin (HCG) hormone supplements while following an extremely low-calorie diet, 500 to 800 calories daily, composed of low carbohydrate and low fat foods.

The diet has changed somewhat in its later form to include vitamin B12 shots, but no other vitamins or minerals are focused on, leaving the person with potentially high levels of B12 and low levels of all the other nutrients. Depending on the form of vitamin B12 used and the person’s MTHFR genetic status, the B12 could be harmful.

No studies have confirmed the diet’s effectiveness, and one in 2016 reported that the hCG injections may contain harmful substances. Another version of this diet utilizes homeopathic preparations of hCG, not subjecting people to harmful excipients, but still, it’s the low calories that are causing the weight loss.

• Very Low Calorie Liquid Diets of the 1970s

Very low-calorie diets consist of 300 to 400 calories daily, and the calories come primarily from protein. In the late 1970s, some doctors gave their obese patients a medically supervised, very low-calorie liquid diet. They also gave them potassium supplements as well. Rapid weight loss occurred but people on this regimen also started dying as a result of the treatment.

One study analyzed 17 case studies of those on this diet for five months and found they died of ventricular arrhythmia. The starvation diet resulted in electrocardiogram changes that caused damage in the heart.

This diet wasn’t sufficient in vitamins, minerals, fat, and carbohydrates, a big problem with many diets.

• The Low Fat Diet of the 1980s

This diet has different variations. One low-fat diet studied contained 10% fat, 75% carbohydrates, and 15% protein and had both a plant-based and animal-based version. The researchers compared them to a low carb diet over a two-week period of time. Those on the low-fat diet ate 145 fewer calories than those on a low-carbohydrate diet, but weight loss was similar.

Low fat diets for long periods of time have been found to reduce sex hormone levels, specifically testosterone. Many doctors have seen low sex hormone levels in lab reports of those on a low fat diet for several years. It’s quite common.

If we take a more holistic view of losing weight by digging deeper into lifestyle, we may find that our daily habits can contribute greatly to our reading on the scale in the morning. One National Health and Nutrition Examination Survey found that those who lost weight and kept it off had several habits in common:

• They engaged in more exercise.
• They ate enough protein and had a higher quality diet with few processed foods.
• They didn’t take diet pills or laxatives.
• They didn’t smoke.

Fad diets will always come and go. The key points to remember are that no matter what, you will always need protein, fat, and a little carbohydrate in your diet. You will always need nutrients, and supplements will be essential since it’s nearly impossible to get all the recommended daily dosages on less than 1500 calories per day. Nutrients are all essential for your survival.