If you're looking for a little extra motivation to lose weight, how about a much better sex life?

We've known for some time that bigger isn't better when it comes to sex. But a new study helps illustrate how you can restore those primal urges – if you shed those pounds.

Researchers working with Dr. Ahmad Hammoud of the University of Utah have learned that the hormonal changes caused by obesity are in fact reversible.

The study, to be published in the Endocrine Society's Journal of Clinical Endocrinology and Metabolism, followed 64 obese men over a two-year period. Researchers checked their levels of reproductive hormones, and also asked questions about the quality of their sex lives.

Over that period, some of those men had gastric bypass surgery, leading to dramatic weight loss.

The obese men, of course, reported unsatisfying sex lives. But those who had the surgery say their sex lives improved along with their weight. The hormonal tests also showed a return to healthy levels in the men who opted for the surgery.

So the researcher concluded that gastric bypass surgery helped improve the sex lives of obese men.

And that's the one big problem with this study.

I'm certain they would have found the same improvements if they followed men who lost all that weight in healthier ways. Gastric bypass surgery is an extreme solution, with sudden and often traumatic post-operative lifestyle changes.

But the study does confirm some of what we already known about obesity and sex. A Duke University study a few years back even found that the obese report 25 times as many problems during sex as folks who have healthy weights.

That's because being overweight can be bad for your sex life in so many ways. Some are obvious – less energy, less mobility and, for many overweight people, less desire. Obesity has also been associated with decreased sperm count and erectile dysfunction.

And then there are the long-term health problems associated with obesity that can also harm your sex life. For example, those extra pounds could lead to diabetes, which has been linked to impotence. And all that fat stores and produces estrogen, which can also dramatically impact a man's sex life.

But there are sensible ways to lose weight – even a lot of weight – without surgery. And it all starts with getting yourself off what I call the "torture chamber diet." The torture chamber diet is loaded with carbs, which spike your blood sugar and are ultimately stored as fat.

Look for a sensible diet with healthy fats and a good balance of whole foods, grains and fresh vegetables. Keep tighter control over your portions, find some exercises you enjoy, and you'll see the weight come off.

It'll take time. But there won't be any torture. In fact, if it improves your sex life, it'll be pleasurable.