Eating disorder researcher Cynthia Bulik once wrote that one of the most perplexing questions about people with anorexia is: “Why is negative energy balance reinforcing for them?” That is, why do people with anorexia seek out negative energy balance?
If you assume the “negative energy balance” here is long term, the answer is obvious: losing weight requires a long term negative energy balance. Isn’t that exactly what people with anorexia want?
That is the popular understanding of the illness, but it’s not really true for many sufferers. Lots of “high functioning” people with anorexia work hard to maintain a stable weight. I was like this myself: by following strict rules for food and exercise, I kept myself just above the “underweight” BMI threshold.
If these long-term sufferers are generally maintaining their weight, we know they’re not in long term negative energy balance. But they still spend a lot of time in negative energy balance: they often work out excessively. Many stretch out the time between meals. Some eat as little as possible during the day and binge in the evening.
Staying in negative energy balance helps people with anorexia relieve anxiety – sort of. Most people feel sluggish and irritable if they miss a meal. People with anorexia feel disciplined and calm. Going into negative energy balance becomes a way to deal with stress. As eating disorder recovery specialist Tabitha Farrar puts it, energy deficits provide “negative state relief.”
The problem is that the anxiety that negative energy balance relieves usually comes from anorexia itself. The illness bombards its victims with intrusive thoughts. It makes them worry that they’ve eaten too much and exercised too little. If they defy it in some small way (like having coffee with milk), it can torture them for the rest of the day. Self-starvation is a trap for people with anorexia – at first it makes them feel better, but over time it leads to a constant stream of bad feelings.