Insulin tends to promote weight gain. But certain types, such as the long-acting insulin Levemir, have less extreme effects.
One study found that people gained nearly 11 pounds on average during their first three years taking insulin. About half of the weight gain is thought to occur in the first three months.
Dr. Cheskin calls the weight-promoting effect of insulin paradoxical. "The things that we use to treat some conditions that are the result of obesity, like [type 2] diabetes, are prone to make you more obese," he says.
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