One of the best examples of the effects of dieting is the Minnesota Starvation Experiment in 1944, O'Malley shared. Thirty six men were selected from a couple hundred volunteers. The goal was to help researchers and relief workers learn how to help people recover from starvation during WWII by studying the psychological and physiological effects of starvation.
The important takeaways to highlight from this study are that after the 'semi-starvation' period of six months where the men ate 1,570 calories per day (3,200 calories a day was normal), the participants reported experiencing depression, apathy, decreased sex drive, decreased strength and stamina, as well as reduced body temperature and heart rate.
They also displayed symptoms of obsession with food - dreaming and fantasizing about food, reading about food, reading cookbooks, talking about food, and savoring their meals with ritual-style eating that prolonged mealtime. Following the study, even after the men were allowed to resume "normal" eating, the participants would binge on large quantities of food, and for some men, this continued later than eight months after the study. "This demonstrates the long-term effects of restriction on the body," O'Malley said.
"This is very similar to what we see in behaviour of not only those who struggle with eating disorders but also very normalized behaviours from those who diet or restrict eating in some way," added O'Malley.
Cadillac added that dieting can also lead to social anxiety, social withdrawal, and feelings of failure. As if that wasn't bad enough, Previte said feeling bad about your weight and constantly dieting can also cause anxiety, poor self-esteem, as well as suicidal thoughts.
O'Malley noted that the men's calorie allowance was definitely low, but not as low as you might think for a "starvation study." She said that "many calorie-tracking apps and meal plans are giving similar numbers and that more often than not, those numbers are underestimating your needs." So while your calories may not be so low that you're starving, they may be so low that they're causing these emotional issues.