After many years of counting calories, we have been resuming the efforts to count calories in order to lose weight for a master’s bout. We don’t need much weight loss and we are not looking to be in a hurry so we set a conservative goal of roughly 2,000 calories per day with the hope of a gradual weight loss.

Two days into the process, you might be listening to you stomach grumbles. You may think, “How the fuck could anyone survive on 1,200 calories per day?”.

Internet experience has taught us  that 1,200 calories per day is enough for a woman who wants to lose a few pounds. 1,500 is sufficient if she is active. It is not possible for a woman to lose weight while still eating 1,800 or 2000 calories per day. This feat would be impossible if she were an Olympic-level athlete who worked out long hours every day.

1,200 calories is what we have heard the whole life. It is also the number we were first exposed to the idea of dieting at a young age.

1.200 calories per day was suggested in the 1920s

Due to a book entitled Diet and Health: with a Key to the Calories, which was widely used by Americans, the idea of eating 1,200 calories per day to lose weight has been around since the 1920s. Despite 100 years of scientific evidence that this recommendation does not work, it will never die. (Another good idea in 1920s was adding radioactive element radium into toothpaste, food and drinks. This was only after many factory workers, mostly young women, died from radium poisoning.)

These diets are rarely successful. Although they may help people lose weight temporarily, people will eventually feel hungry and abandon the diet. They usually gain back as much as they have lost. Jamie Nadeau is a registered dietician that helps people to heal their relationship with food. “They either couldn’t stick with it because they didn’t have enough food or they had a bad relationship with food.”

That’s because 1,200 calories per day is considered a starvation diet for most women. Nadeau stated that most women need more than 1,200 calories to maintain their normal survival functions. “It is absurd that people try to live on this, and exercise on such a small amount of calories.”

Half of a woman’s daily energy requirements are met by 1,200 calories

Recent research published in Science in August found that the average adult woman aged 20-60 burns approximately 2,400 calories per day. This is an average woman. Women who are smaller or have a slower metabolism burn more calories than women who are larger and/or have faster metabolisms. Herman Pontzer, a Duke University faculty member, stated that 1,200 calories per day is about half the amount that the average woman needs.

Contrary to what our fitness trackers tell us, our bodies don’t have a low energy requirement and we don’t “earn” the right for extra calories whenever we move. Our bodies evolved to consume a fixed amount of energy every day. This is called “constrained total daily energetic expenditure.”

This means that, although exercise is important for long-term health and weight maintenance, it won’t help you lose weight.

Our bodies instead act as if our daily energy consumption is a fixed budget. It will shift to different processes to make it equal at the end of each day. Then, we start over the next day.

Sedentary people will use their extra energy for more expensive processes such as the immune system and stress response. These are small things that help us fight off infection and escape danger but can lead to long-term diseases.

When we are active, like when training for something, our bodies may burn more energy temporarily, but eventually they will adapt and our energy needs will return to a level that is close to our daily average.

If we gain muscle, our metabolism will rise along with our daily energy requirements due to an increase of our fat-free mass. As our brain works to maintain a steady weight, our hunger will increase. This is essential for survival in human history.

The Minnesota Starvation Experiment uses 1,200 calories per day

The average energy requirement for women is 2,400 calories per day. This would mean that a 1,200 calorie diet would be comparable to the Minnesota Starvation Experiment in 1944. It was designed to determine the best way to refeed those who are starving.

36 healthy, young men were recruited to participate in this study. The first three months were used to calibrate the daily food intake. These volunteers survived on an average of 1,570 calories per day for six months, approximately half their daily caloric requirements. They lost an average of 25% of their bodyweight over the course these six months. The last three months were spent allowing participants to eat as much or as little as they liked.

Participants developed a food obsession that continued long after they had stopped starving. Participants also experienced anxiety and depression as well as eating habits similar to those with anorexia or bulimia.

The Minnesota Starvation Experiment participants were motivated volunteers. Participants believed that their participation would help starvation victims and they could also live and eat in a controlled environment. They developed problems that continued long after they were starved.

A cycle of disordered or deprivation eating can result from a diet

A person may eat 1,200 calories a day for a few days and then they’ll be able to survive on that amount for several more days if they’re very motivated. After that, they will typically stop the diet and eat more to compensate for the loss.

They might also not be accurately counting. Pontzer stated that people are not good at tracking their food. Pontzer said that it is possible that dieters who aim for 1,200 calories per day might end up with a lower reduction.

These diets will not work for the majority of people. They will gain weight again and develop a disordered relationship to food. Nadeau stated that the main problem with 1,200 calories per day is that people are not able to keep it up.

Diet culture is not an easy problem to solve

This isn’t a “we” talking about healthy eating. We include myself in the discussion. Nadeau recommends a similar approach to clients she works with. She encourages them to create habits that bring joy to their lives, and not take away anything. Nadeau stated that it is important to be proactive and say “I’m no longer going to die anymore, I’m going to eat less, or restrict my diet for weight loss,” Instead, she suggests focusing on creating good habits that improve our lives, such as eating more vegetables, fiber-rich proteins, and engaging in physical activity.

This may seem like extreme advice in the world we live, but it is common sense in a more disorderly world. Our disordered thoughts about nutrition and health are more widespread than we realize. It has been many years since we considered 1,200 calories per day an adequate amount of food. Yet, despite all the information we have about the body and what it needs, some still feel that 2,000 calories per day is too much.