People can be obese yet physically healthy and fit and at no greater risk of heart disease or cancer than normal weight people, say researchers.The key is being "metabolically fit", meaning no high blood pressure, cholesterol or raised blood sugar, and exercising, according to experts.Looking at data from over 43,000 US people they found that being overweight per se did not pose a big health risk.The results are published in the European Heart Journal.In the study at the University of South Carolina, more than a third of the participants were obese.Of these 18,500, half were assessed as metabolically healthy after a physical examination and lab tests.This subset of metabolically healthy obese people who did not suffer from conditions such as diabetes, high cholesterol or high blood pressure, were generally fitter and exercised more than the other obese people.And their risk of developing or dying from cardiovascular disease or cancer was identical to people of ideal weight and was half that of "metabolically less fit" obese people.