Cocaine doesn't just curb appetite, it suppresses the body's ability to store fat too, find scientists Previously thought coke caused loss because it suppressed the appetite But a new study found that the class A drug prevents fat storage However the slimming effect stops when users stop taking the drug Some people are thought to relapse because they are upset by the weight gain caused abstinence Taking cocaine prevents the body storing fat, new research has revealed. Previously experts believed cocaine users were slim because the class A drug was suppressing their appetites. The new research, by scientists at the University of Cambridge, also found that the slimming effects stop when users "go clean" and that this can lead to dramatic weight gain. Taking cocaine prevents the body storing fat, new research has revealed The findings support theories that body-conscious drug users sometimes relapse because they become so unhappy at gaining weight when they stop taking cocaine. Dr Karen Ersche, from the Behavioural and Clinical Neuroscience Institute at the University of Cambridge, compared 30 cocaine-dependent men to 30 healthy ones. She found that cocaine users actually choose worse diets than healthy men - opting to eat fatty foods and carbohydrates - but that they lose weight regardless. Meanwhile, levels of appetite-controlling hormone leptin in the drug-users" bodies were cut leading to severe over-eating. Previously experts believed cocaine users were slim because the class A drug was suppressing their appetites Researchers believe the habitual overeating, and poor diet, only confound the weight-gain when users" metabolisms slow when they come off the drug. Dr Ersche said: "We were surprised how little body fat the cocaine users had in light of their reported consumption of fatty food. It seems that regular cocaine abuse directly interferes with metabolic processes and thereby reduces body fat. This imbalance between fat intake and fat storage may also explain why these individuals gain so much weight when they stop using cocaine. For most people, weight gain is unpleasant but for people in recovery, who can gain several stone, this weight gain goes far beyond an aesthetic concern but involves both psychological and physiological problems. The stress caused by this conspicuous body change can also contribute to relapse. It is therefore important that we better understand the effects of cocaine on eating behaviour and body weight to best support drug users on their road to recovery. Notable weight gain following cocaine abstinence is not only a source of major personal suffering but also has profound implications for health and recovery. Intervention at a sufficiently early stage could have the potential to prevent weight gain during recovery, thereby reducing personal suffering and improving the chances of recovery. The research was published in the August edition of the scientific journal, Appetite.