Looking at something like anorexia nervosa, which is associated with resistance to eating and weight loss, you are watching for rapid and severe weight loss because of diet, calorie counting and food restriction. People often develop a list of foods they cannot eat. They start becoming vegetarian, and subsequently vegan. It’s difficult to recognize these signs, because people do these things to be health conscious, but we also see this in anorexia.

Extremes in exercise are also a sign. It’s a difference between going for a run a few miles twice a week versus going for a run 10 miles twice a day. We’ve been in contact with some universities who have the gym staff report if people are spending too much time there, and ban them from the gym.

Some people start wearing baggy clothes, despite a lot of weight loss, because they feel like they have to hide their body. The other thing to notice is that people may feel down or depressed. Significant weight loss may mimic depression because of lack of energy, low mood and sleep difficulty, which are all associated with not getting enough nutrition.

In bulimia nervosa: where people have binge eating episodes, you look for fluctuating weight. You might also find evidence that they are using laxatives, diuretic use, or evidence of vomiting around the toilet. Sometimes families will find it in tupperware containers in closets. Other signs can be disappearing food from the kitchen and calluses on the hands, from self-induced vomiting……

Experts Answer: How Do You Tell if Someone Has an Eating Disorder? | Signs & Symptoms of Anorexia, Bulimia | MyHealthNewsDaily.com.