Does losing weight improve erections?

The question

Obesity and erectile dysfunction often go together. Excess weight is linked with inflammation, damage to the lining of blood vessels and changes in hormones, all of which can affect erections. Doctors have long advised men with ED to lose weight and move more, but for years much of the supporting evidence came from observational studies, which show that two things travel together without proving that changing one changes the other.

The question this study set out to answer was simple: if obese men with ED actually change their lifestyle, do their erections improve?

The study

The trial was run by researchers in Italy and published in JAMA in 2004. It enrolled 110 men aged 35 to 55 who were obese and had erectile dysfunction. Importantly, none of them had diabetes, high blood pressure or high cholesterol, so the researchers could look at the effect of weight and activity without these conditions muddying the picture.

The men were randomly assigned to one of two groups:

• Intervention group: detailed, personalised advice and regular support to reduce calorie intake and increase physical activity.
• Control group: general information about healthy food choices and exercise.

Both groups were followed for two years. Erectile function was measured with a standard questionnaire used in ED research, which gives a score for how well erections are working.

What they found

The men in the intervention group lost more weight and became more active than the controls, and their erectile function scores improved. By the end of the study, about one third of the men in the intervention group had regained normal erectile function, according to the questionnaire. In the control group, very few men did.

Markers of blood vessel health and inflammation also moved in a favourable direction in the intervention group, which fits the idea that lifestyle change helps erections by improving the health of the blood vessels.

What it does NOT prove

• It does not show that everyone will improve. Around two thirds of the intervention group did not regain normal function, even with substantial support.
• It does not cover all men with ED. Men with diabetes, high blood pressure or high cholesterol were deliberately excluded, and many men with ED have at least one of these. The men were also middle-aged, obese and from one country.
• It cannot separate diet from exercise. The programme combined both, so the study cannot say which mattered more.
• It was not blinded. Men knew which group they were in, which is unavoidable in lifestyle trials but can influence questionnaire answers.
• It was one trial of modest size. A single study of 110 men is strong evidence for its setting, but it is not the final word.

Why it matters

This was one of the first randomised trials to show that changing lifestyle, rather than simply having a healthier lifestyle to begin with, can improve erectile function. Current guidelines from the American Urological Association and the European Association of Urology both recommend addressing weight, physical activity and other modifiable risk factors as part of managing ED.

That does not mean men must wait months for help. Lifestyle change and medical treatment can run side by side, and the effort pays off beyond the bedroom, because the same blood vessels supply the heart. Our erectile dysfunction guide explains the full range of options.

Questions men also ask

How much weight do I need to lose to help erections?

There is no single target. In the trial, men who lost more weight and became more active tended to improve more, but a doctor can help set realistic goals for you.

Can I take ED medication while I lose weight?

In many cases, yes. Guidelines treat lifestyle change and medical treatment as complementary, and a doctor decides which medicines are suitable for you.

Does exercise help erections even without weight loss?

Physical activity supports blood vessel health in its own right, and guidelines recommend it for men with ED, but this particular trial tested diet and exercise together.

Sources & further reading

1. JAMA Effect of lifestyle changes on erectile dysfunction in obese men: a randomized controlled trial (opens in a new tab) (2004) Esposito K, et al.
2. Journal of Urology Erectile Dysfunction: AUA Guideline (opens in a new tab) (2018) Burnett AL, et al.
3. European Urology European Association of Urology Guidelines on Sexual and Reproductive Health—2021 Update: Male Sexual Dysfunction (opens in a new tab) (2021) Salonia A, et al.

This article is general health information. It does not replace an individual medical consultation, examination or diagnosis. Read our editorial policy and medical review policy.