By Jimmy Downs

Saturday April 13, 2013 (foodconsumer.org) -- A study in Diabetologia suggests that eating too much grassy saturated fat and total fat, which is found high in meat and some dairy products, may increase the risk of type 2 diabetes mellitus or insulin resistance.

J.A. Marshall and colleagues analyzed data from 1069 Hispanic and non-Hispanic white individuals aged 20 to 74 years in Southern Colorado who tested normal on a glucose tolerance test or did not have type 2 diabetes mellitus to see how dietary factors affect fast serum insulin levels and found high intake of saturated fat and total fat was linked to high serum concentrations of fasting insulin.

From all participants, 24-hour dietary information was collected three times during a 8-year period and each time a blood sample was tested to determine the fasting insulin concentration.  The serum fasting insulin concentrations were found significantly higher in individuals who were younger, female, of Hispanic ethnicity, having higher body mass index, higher waist circumference and lacking physical activity.

Dietary factors found correlated with higher fasting insulin concentrations include total fat and saturated fat.  The associations were already adjusted for age, sex, ethnicity, BMI, waist circumference, energy intake and physical activity status.  Monounsaturated fat and polyunsaturated fat which are found in plant-based foods were not associated with fasting insulin concentrations.

Intake of dietary fiber and starch was found inversely associated with fasting insulin concentrations.

Ironically, intake of sugars that are commonly considered risk factors for type 2 diabetes mellitus including sucrose, glucose and fructose was not associated with fasting insulin concentrations.

The researchers concluded "These findings support animal studies and a limited number of human population studies which have suggested that increased saturated and total fat intake and decreased fibre and starch intake increase fasting insulin concentrations and may also increase insulin resistance."

In addition to their effect on the risk of type 2 diabetes mellitus, saturated fat and trans fat can increase the risk of heart disease and potentially some cancers.

Trans fat is found in processed foods and restaurant-served foods and saturated fat is found largely in animal-based foods.    Fats considered healthy such as polyunsaturated fat and monounsaturated fat are found in plant-based foods such as vegetables and nuts.

Those who want to reduce their risk for type 2 diabetes mellitus should consider cutting back on their intake of meat and high fat dairy products and increasing intake of fiber-rich vegetables and starch based foods.  Those who already have prediabetes may want to try curcumin at a dose of 6 grams per day to prevent the condition from processing to become diabetes, an Indian study suggests.