However, information from clinical studies is scarce. Acute caffeine and/or coffee consumption have been associated with impaired glucose metabolism and insulin resistance. In relation to inflammation, animal studies have indicated a beneficial or no effect of coffee consumption, whereas a clinical study in humans found an increase in adiponectin and a decrease in interleukin-18 (IL-18) blood concentrations after a monthly intervention including daily consumption of 8 cups of coffee. As far as energy balance is concerned, there is an early experiment demonstrating that the ingestion of 300 mg of caffeine prior to food intake, compared to the non-caffeine intake, significantly reduced energy intake by 21.7% in men, but not in women. A more recent study has found that the combination of caffeine and red pepper is positively associated with energy expenditure and negatively with energy intake, whereas, it has also been reported a positive association between habitual caffeine intake and body weight loss achieved through a very-low-calorie diet.