The world-wide obesity problem is only worsening. It has been proven that increasing energy expenditure is an effective prevention method for obesity. But do simple methods increase the energy expenditure? It has been shown in a previous study that the goji berry stimulates a metabolic reaction and increases the energy expenditure, however, the quantity and/or portion of the berry needed to give an effect is unknown.

By the outcome of another study we know that postprandial oxygen consumption after eating goji berries increases in humans. However, this cannot be assumed with 100% certainty. Energy expenditure and substrate oxidation can only be accurately determined by measuring both the oxygen consumption and carbon dioxide production.

In this study, two treatments were carried out by healthy, overweight men between 18 and 65 years old. The subjects were divided into two groups, one test group and a control group. Each underwent two identical treatments. Indirect calorimetry, measured with the Omnical ventilated hood, was applied for 30 minutes to determine the basal metabolic rate. After a meal, the measurements were continued. The subjects were given a meal containing 25 grams of goji berries or an equivalent with the same nutrients.

Between the two treatments there was no visible change in energy expenditure, but after a meal energy expenditure rose significantly.  The VO2 and VCO2 values did not differ between the goji berry meals and the control meals. The RQ over time was not sensitive to the ingestion of goji berries. Very small differences in the same range are measured, which means that the Omnical is a very accurate and reproducible device.

This study indicates that a single dose of goji berries does not affect postprandial energy expenditure and substrate oxidation in healthy, overweight men.