A study from the University of Illinois (UI) says that obese adults can lower their cholesterol by 10 points by eating a diet that is high in unsaturated fat but low in saturated fat.

Nutrition scientists at UI analyzed the findings of eight randomized but controlled trials, investigating the difference in blood lipid levels and body composition that came from diets that provided similar amounts of calories but had differing amounts of either saturated or unsaturated fats. 

Compared with their counterparts, subjects who ate greater amounts of monounsaturated fats and polyunsaturated fats reduced their total cholesterol by more than 10 milligrams per deciliter.

However, reductions in these low-density lipoprotein (LDL) levels - often considered "bad cholesterol" - and triglyceride concentrations were marginal, said lead author Bridget A. Hannon, a graduate research assistant at the university.

However, regardless of how many saturated or unsaturated fat they consumed, only those subjects who followed calorie-restricted diets lost weight, the UI scientists found.

Polyunsaturated and monounsaturated fats, commonly called the "good fats", are found in foods such as olives, sunflower and canola oils, nuts and seeds, and avocados. Consumption of these unsaturated fats has been linked with lower risk of cardiovascular disease and other health benefits. While saturated fats, usually found in animal products, such as butter and dairy, have been linked to weight gain and an increased risk of cardiovascular disease.

Obesity has been linked with more than 20 different diseases, and UI scientists found lowering total cholesterol by as little as 10 points can be clinically beneficial in preventing the development or progression of many of these conditions.

Even if people who are metabolically healthy but overweight have not yet developed any weight related comorbid diseases or conditions. "We know that metabolic health, in the context of obesity, is a transient state that may not persist over time, and these individuals are at increased risk of developing different comorbidities," said co-author Sharon V. Thompson, a registered dietitian and pre-doctoral fellow at the university.

Statistics show that more than 60 percent of adults in the US are obese or overweight, placing them at greater risk of weight-related diseases including high cholesterol and strokes.

The study, published recently in the Annals of Nutrition and Metabolism, is believed to be the first to examine the effects of replacing saturated fats with unsaturated fats in the diets of more than 660 metabolically healthy individuals who were overweight or obese.