A Brief History of Fad Diets

Last week, we talked about the importance of dietitians when it comes to patient education. When speaking with patients, it is essential to equip them with tools to help identify pseudoscientific or distorted health claims. A good rule of thumb is that if any diet promises massive payoffs for very little input, there’s probably something a bit fishy. It’s important to emphasize that no one modification will radically change your body that quickly, and it’s not even healthy to shed weight too quickly! Besides, while achieving a healthy goal weight may be a goal for many of your clients, the wonder of a well-balanced diet is that it will touch on many areas of your health.

Just in time for Halloween, we’re covering some super spooky nutrition fad diets throughout history. Our ideas of what constitutes a healthy diet are always evolving. As our scientific knowledge advances, we are better able to hone in on what the body needs to function at its best. While it may seem obvious to us that maintaining a healthy diet and healthy body require a lot of work and planning, people have been looking for a quick fix for weight loss for over 2,000 years! Along the way, we’ve seen our fair share of fad diets, which range from bizarre to downright scary. Here are some of our favorites:


Tapeworms are parasitic worms that can live in the gut and grow up to 30 feet long. They also have been touted for their weight loss capabilities. Back in the 19th century, people would intentionally ingest tapeworms in the hopes of shedding a few pounds. While this is horrifying on its own, according to the CDC, infection with tapeworms can lead to a disease that causes epileptic seizures!

The Grapefruit Diet

Throughout the 1970s and 1980s, those aiming to lose weight consumed massive amounts of grapefruits. While this fruit is still a popular and healthy choice, moderation is key! Grapefruit can interfere with enzymatic activity and alter hormone levels in the blood – it can also interfere with various medications.  


Many products marketed as supplements for weight loss are actually quite dangerous. They are not always labeled properly and may contain ingredients that are contaminated or even prohibited by law. Often, they don’t have their intended result, as they haven’t been properly tested in humans. 

Like (or hate) what you see? Check out this list of more weird and spooky dieting fads. How do you talk to your patients about outrageous dieting claims? Do you know of any other outrageous diet claims from the past? Comment below!