There are two common body shapes that develop when fat accumulates, apple shapes appear when fat collects in the abdominal area, this is termed upper body obesity (UBO). The other body shape is pear, when fat resides on the hips, which is known as lower body obesity (LBO).

Researchers from the Netherlands have investigated if the way the body deals with consumed fatty acids is different in men with upper or lower body obesity.  Previously research has shown that the chain length of dietary fatty acids is important in affecting fat absorption, fat metabolism and fat transportation around the body.

Medium chain triglycerides (MCT) are a type of dietary fatty acids which passively diffuse to the portal system (a system of blood vessels), without requiring modification or bile salts for digestion. Rich sources of MCTs include coconut oil and palm kernel oils. Some studies have shown MCTs can help the process of excess calorie burning and weight loss although almost half of the calories in your diet would have to come from MCTs themselves. 

Polyunsaturated fatty acids (PUFA) compared to MCTs are longer fatty acids which are absorbed into lymphatic system.  PUFA can be found in grain products or sea food. Beneficial PUFA include Omega-3 fatty acids found in fish, which reduce the risk of heart attacks and Omega -6 found in sunflower oil which can reduce the risk of cardiovascular disease.  However, high consumption of Omega 6 may increase the developmental risk of breast cancer in postmenopausal women or prostate cancer in men.

It has been suggested that within the body PUFA is disposed to the periphery (organs, muscles or subcutaneous fat) and MCT disposed more centrally. As MCT are often rapidly broken down than stored, a diet rich in MCT has been advised to people suffering from obesity problems

In the study published in this month’s Genes and Nutrition journal, researchers profiled adipose tissue biopsies from mildly obese men to investigate the effect of body fat distribution on the physiological response to two dietary fat interventions. Subjects with a BMI of 27-35 participated in the research.  Men with Waist to Hip Ratio (WHR) <1 were considered LBO and WHR>1 as UBO. As part of the trial they consumed a spread containing predominately either PUFA (71% long-chain fatty acids) or MCT (65% medium- chain fatty acids). Each day the subjects consumed 60g of the spread for two weeks.

The results showed a negative regulation of the metabolic pathways (lipid, carbohydrate and amino acid metabolism) in upper body obesity subjects when they consumed MCT compared to a PUFA diet. Despite previous recommendations that a  MCT based diet improves obesity traits, the findings from this study suggests a MCT diet in apple shaped people may have an adverse effect with increased inflammation and decreased energy metabolism in adipose tissue.

Dr Marijana Radonjic the papers author, reports that as there are different physiological characteristics of upper and lower body obesity, fat distribution is an important parameter to consider when selecting a personalized dietary regime.