Why crash diets leave you so low

BEING underweight is linked to depression, a study found this week. This isn’t the first time research has shown this.

The fascinating Minnesota Starvation Experiment, carried out in the U.S. in the Forties, looked at the impact of restricted diets to guide relief assistance to famine victims in Europe after World War II.

Volunteers were put on a diet of about 1,500 calories a day plus exercise to lose a quarter of their weight in six months.

What the researchers found shocked them. Many on the diet experienced severe distress and depression. Some resorted to self-mutilation: one amputated three of his fingers with an axe.

As well as hallucinations, the volunteers showed a marked decline in concentration and comprehension.

Such studies are often cited as a factor in the high rates of other mental health issues in patients with eating disorders. But I think they also show why crash diets make people miserable. In the short term, the drop in blood sugar leads to irritability and mood swings.

Over a longer period, cutting calories can trigger serious depressive illness.

Losing weight needs to be done slowly with small, sensible changes rather than simply slashing calories.

Or else one problem — being overweight — is simply replaced with another.