For weight loss, popular diets advocate everything from eating according to your blood type to nearly fasting for 2 days a week. Now, one popular instruction - to eat small but frequent meals throughout the day - has been called out by researchers, who say it does not boost metabolism or encourage weight loss.

In fact, the research - presented today at the Society for Endocrinology annual BES conference - suggests counting calories is all that really matters when it comes to losing weight. Obesity has become a growing public health concern in recent decades. According to the Centers for Disease Control and Prevention (CDC), the percentage of adults over the age of 20 who were overweight or obese in the US as of 2010 was nearly 70%.  The researchers of this latest study, led by Dr. Milan Kumar Piya of the University of Warwick in the UK, note that previous research has suggested eating a single high-fat meal increases low-level inflammation in the body when bits of gut bacteria - known as endotoxins - enter the blood stream. Since this kind of inflammation has been linked to a future risk of developing cardiovascular disease and type-2 diabetes, the researchers wanted to investigate whether eating often would cause more damage that might increase these risks in obese individuals. To conduct their study, the team analyzed 24 lean and obese women who were given two meals or five meals on separate days. These women consumed the same number of calories on both days, and the researchers meanwhile measured their energy expenditure using whole body monitor calorimeters.