Whether it's possible to be both fat and fit has been a hotly debated topic for years.

The latest: A study of 1.3 million Swedish men found that over 30 years, normal-weight men at any level of fitness had a lower risk of premature death than the most physically fit obese men, researchers reported last month in the International Journal of Epidemiology.

The study wasn't designed to prove cause and effect, however - simply an association between fitness and the risk of premature death.

There are plenty of data connecting obesity with diseases, from cancer to heart disease to diabetes. Yet many other studies prove what dieters already know - it's extremely difficult to lose weight and keep it off permanently.

But there's some positive news, too. Numerous researchers have found that interventions beyond traditional weight-loss diets - such as improved nutrition, getting more activity, and challenging the negative myths and assumptions related to size - have powerful benefits.

What doesn't work: Nagging, shaming, and blaming obese people for their size.

Among the research findings:

Modest changes in eating, activity, and weight can help normalize the metabolic profile of obese people, according to a 2013 study published in the New England Journal of Medicine.

Intuitive eating - defined as eating only when hungry, stopping when full, and choosing foods according to personal preference - is associated with both lower BMI and better psychological health, according to a review of literature on the subject last year in the journal Public Health Nutrition.

The chronic stress of weight loss and gain, plus feelings of shame over weight, are associated with high cholesterol and blood pressure as well as insulin resistance, a study published in the Journal of Community Health found.

Simply knowing the health risks of obesity often does not increase efforts or success in losing weight (Nutrition Journal, 2011).

Obese people who are led to believe they will be happier and healthier if they diet and exercise frequently experience only more guilt, blame, shame, and feelings of failure, a 2010 study in the journal Public Health found.

- Diane R. Girardot