All Dietary Theories
An Index of Popular and Historic Diets
Why So Many Diets Exist
Dietary theories have shifted as human needs, goals, and beliefs about health have changed. Some plans come and go as trends, while others stick around for decades. Science plays a role, marketing plays a role, and so does our long-standing desire for bodies that feel good, perform well, and look a certain way.
One person’s food can be another person’s poison.
The Modern Food Landscape
The way we eat today looks nothing like it did a few generations ago. Foods are more processed, ingredient lists are longer, and many things don’t even resemble what they started as. It’s no surprise that food sensitivities and allergies are more common now. When trying a new eating plan, slow down and pay attention. A good rule of thumb? If it grows in the ground, great. Tip: Eat plants, not what’s made in a plant.
So, what gives?
One Size Never Fits All
Just because a diet works wonders for someone else doesn’t mean it will work for you. This is called bioindiviuality. There is no single “right” way to eat—only what supports your body where it is right now.
When What Worked Stops Working
A lot of people hit a point where the plan they relied on for years just… stops working. Weight changes, energy drops, and frustration are at their peak. Hormones shift, needs change, and nutrition has to adjust along with it.
Sustainability Matters More Than Speed
Fast results usually disappear just as fast. Sustainability is key. If a plan feels miserable or overly restrictive, it won’t last—no matter how convincing the promise sounds.
How to Use This Index
This page includes a comprehensive list of dietary theories that have been researched, taught, or promoted at different points in time. Some may feel familiar, others may sound strange—but each reflects a moment when science, culture, or medicine pointed people in that direction. Click any diet to see a summary that takes only a minute or two to read. If you’d like to only see the Top 25, you can find them here.
WARNING: Because some of these theories can be unhealthy or unsustainable, make sure you discuss any dietary changes with your doctor. It is highly recommended that your physician complete a full blood panel to determine the nutrients you need and allergy tests. Allergies or sensitivities to wheat, eggs, dairy, soy, shellfish, and gluten are very common, and many people have no idea that sometimes this is the actual source of their dietary problems.
The Dietary Theories:
Japanese Women Don’t get Old or Fat
Rainbow Green Live-Food Cuisine Diet
South Beach Diet Gluten Solution
Weston A Price Foundation Diet
