Apparently, there is a lot of ignorance and confusion out there when it comes to weight loss / weight management and everyone tries to use their logic or intuition to explain this.

So you read worst answers such as "they have a slow metabolism" or "fat people lie about eating less", etc. But the true reason why so many people are overweight and Everybody eats the same food.

It’s been observed that 99% of people eat pretty much the same food. About 70% of the population will end up having a weight problem while the remaining 30% (I call them genetic freaks) will be able to maintain a healthy body weight. What kind of food is everybody eating? Junk food, fast food, sugary beverages, meat and processed carbohydrates.

 

The industrial revolution is to blame for the modern pandemic of obesity in the 1st (and now 2nd) world countries. And it’s not because food became cheap and abundant so everybody eats too much. People get overweight because the food they eat is very different from the food our ancestors used to eat for thousands of years.

Here’s the food our ancestors used to eat

Caveman era

Tubers / leaves (often)

Vegetables / Fruits (often)

Meat (extremely rare)

Oil / Sugar (didn’t exist)

Fast food / junk food (didn’t exist)

Agrarian era

Unrefined wheat, rice, beans, potatoes, corn, etc (often)

Vegetables / Fruits (often)

Meat (extremely rare unless they were wealthy)

Oil / Sugar (extremely rare unless they were wealthy)

Fast food / junk food (didn’t exist)

Modern era

Meat (often)

Processed carbohydrates (often)

Fast food / junk food (often)

Oil / Sugar (nearly in every food)

Unrefined wheat, rice, beans, potatoes, corn, etc (rare)

Vegetables / Fruits (extremely rare)

Did you notice the change in the type of foods humans ate during different time periods? With each advancement from the caveman era, to the agrarian era and to the modern era the food was becoming more calorically dense.

 

Our bodies rely on stomach stretch receptors to tell us when we need to stop eating. In order for the stretch receptors to work properly, you need to eat the foods that are low in caloric density (green bars in the image above). People who used to live in the caveman and agrarian ages didn’t have a weight problem because they mostly ate the foods that were low in caloric density.

Modern humans, on the other hand, are living in the modern age and eating foods that are very high in caloric density (red bars in the image above). Our stomach stretch receptors aren’t able to properly measure the calories in food and tell us when to stop eating, so most of us will end up overeating. 

The majority of people in the modern times will gain excess weight because they are eating foods that are too calorically dense. However, our bodies also rely on nutrient receptors to calculate a caloric value of a meal.

Unfortunately, the digestive system of the majority of people doesn’t have enough of these nutrient receptors and relies mostly on the stomach stretch receptors while about 30% of the population can get away with eating such calorically dense food because they have more of the nutrient receptors compared to an average person.

So while an average person will overeat after eating a calorically dense meal, a "genetic freak" will not because their hunger can be squelched with less food.

Most people are overweight despite eating little food because they are eating calorically dense foods such as pizza, hot dogs, meat, sugary drinks, oil, etc. If they change the type of food they eat and start eating more vegetables, fruits, legumes, whole grains, and complex starches (brown rice, oatmeal, corn, etc) they’ll be able to lose and maintain a healthy body weight.