Paleo, Keto, Vegan, Mediterranean, Zone, Atkins. It seems like there’s as many diets as there are people. Each one promoted as better than the rest with religious-like zeal. Any other diet might as well be part of the Dark Side. And it seems the more radical the diet, the more excitement it generates.

When we think of diets, we usually picture people trying to lose weight. Most likely by eating less and being told not to eat foods they like. It’s no wonder why some people refer to diet as ‘die’ with a ‘t’ at the end.

Indeed, many of popular diets are geared only for weight loss and nothing more. As if losing weight is the only benefit of watching what you eat.

Fad diets weight loss

When it comes to weight loss, most diets work in the short-term. Very few diets have been studied for more than a year or compared head-to-head. What we do know is weight loss can occur equally whether on a low fat or low carbohydrate diet. Although the Atkins diet (which focuses on high protein and high fat) may result in greater weight loss compared to other popular diets.

Of course these studies are done under ideal conditions. People are counselled on what to eat (or in some cases given the food) and closely monitored with regular check-ins with dietitians. In addition, only very motivated and disciplined people go into these studies.

But that’s not how things work in the real world. No one’s watching us or telling us what to eat. And with all the temptations, healthy eating is a constant challenge, let alone trying to lose weight. For those of you who have been successful losing weight, you probably know that keeping it off is that much harder. Even contestants of The Biggest Loser regain much of the weight they lost.

Food is Needed for Survival

There’s more to dieting than weight loss. The main purpose of eating isn’t so we can go back in time and look good in our high school graduation suit or prom dress. And regardless of what we eat, we all have a diet. While it may not be as structured as one of the popular diets, most of us only eat between 30 to 50 different foods throughout the year.

To state the obvious, we need food to live. So starving oneself with the aim of weight loss is not healthy. Food isn’t like smoking in which the best number of cigarettes is zero. Having zero calories may help with losing weight but not much of anything else.

The primary purpose of our diet is to keep us alive. The foods we eat provide the nutrients and calories needed for our body’s function. From breathing to the beating of our heart to even metabolizing the foods we eat, food keeps us going. Even if you were to do nothing all day, you would probably need to eat somewhere between 1300 and 2000 calories per day.

food is medicine

Food also does more than just keep us alive. It helps prevent disease and keep us healthy. This was realized more than 2000 thousand years ago when Hippocrates said Let Food be Thy Medicine, and Medicine be Thy Food.

However, it wasn’t until the past 50 years that science caught up to this belief. This paralleled the rise of industrial food production in which more advanced ways developed to produce and preserve food. These practices benefited society as foods became more accessible and cheaper. At the same time, however, it gave rise to ultra-processed foods which have questionable nutritional value.

Food is More than Just its Components

Research into diets began by looking at foods based on their components of macronutrients (fat, protein and carbohydrates) and micronutrients (vitamins, minerals). Early studies focused on fat and came to the conclusion it was bad for us. The result was a switch to diets of lower fat, higher carbohydrate and lower protein. Not only did people reduce their fat intake, but foods were created with added sugar instead of fat. It’s believed that this shift away from fat to sugar and simple carbohydrates has contributed to the rise in obesity.

But we don’t eat foods as isolated macro- and micro-nutrients. We eat whole foods. And we eat a mix of foods. One meal doesn’t consist of only fat or only protein. So studying components of foods in isolation doesn’t reflect how we eat. This may be why studies show no benefits from eating vitamins in pills. Similarly, diets that focus only on nutrients are missing the point of food.

Instead, we eat patterns of foods. Many of the newer popular diets are focused on food patterns. These diets recommend types of foods, whether it be meat, dairy, fruits or vegetables, as opposed to the amount of carbohydrates and vitamins.

Despite the popularity of many diets, only a few have been studied for their health benefits. The DASH diet (one of low sodium and fat, high on fruits and vegetables) has been proven to reduce blood pressure and there is evidence the Paleo diet can help improve blood sugar in people with diabetes. Perhaps the best studied diet for long-term health is the Mediterranean diet. This diet has been shown to reduce the chance of early death in people with heart disease as well as preventing heart disease in those without it.

What is the best diet?

So then which really is the best diet?

It’s unlikely that there is one diet which is better than any other for all people. It can depend on your health goals as well as your current health. Even in weight loss studies, not all people respond the same. Some people lose more weight than average and some people may not lose any.

The one common factor of diets such as Paleo, Vegan and Mediterranean is their focus on natural foods while avoiding processed foods and those with added sugar. This may be the most valuable advice of all from these diets. It’s also consistent with diets of some of the healthiest populations in the world such as the Tsimane in Bolivia or people in Okinawa.

In the end, the best diet is the one that avoids processed foods and you’re able to maintain for the rest of your life.
