Although spicy food and its bioactive ingredients — mainly capsaicin — have been shown in previous studies to improve metabolism, reduce obesity-induced glucose tolerance, and control appetite, conflicting reports say "spicy food consumption is positively associated with BMI, waist circumference, and other obesity measures in Chinese adults", especially in rural China.
Researchers from China's Zhengzhou University recruited a total of 15,683 subjects (5,907 male and 9,776 female) aged between 35 and 74 years for a cross-sectional study that was part of the Rural Diabetes, Obesity and Lifestyle (RuralDiab) study, which was conducted in the country's Henan province between July 2015 and September 2016.
Weighing in spicy
They observed that the general prevalence of obesity among the participants as 17.57%, and stated that "the increase in spicy flavour and spicy food intake frequency were associated with the high ratio of general obesity and high BMI values".
They added that "the meta-analysis (of the cross-sectional study) showed that participants having spicy food had higher BMI values, which was consistent with the result of the present study".
Additionally, compared to those who did not eat spicy food, there was a higher obesity rate among those who ate spicy food: the spicier the food and the more frequent the intake of spicy food, the higher the obesity rate.
What's really cooking?
However, the researchers went on to state that cooking methods and ingredients might explain the positive association between spicy food consumption and general obesity.
For instance, more oil is used when making certain types of chilli sauces, and chilli oil is commonly used to add flavour to Chinese dishes.
Furthermore, the consumption of spicy foods may be accompanied by a higher intake of carbohydrate-rich foods to alleviate the resulting burning mouthfeel.
Correlation, not causation
Because of this, the researchers wrote: "This cross-sectional study only determined the association between spicy food consumption and general obesity, but failed to establish a cause-and-effect relationship."
They concluded: "Multi-centred, long-term follow-up studies are needed to pay more attention to the relationship between spicy food and weight management."
Source: Nutrition, Metabolism & Cardiovascular Diseases
"Relationship between spicy flavor, spicy food intake frequency, and general obesity in a rural adult Chinese population: The RuralDiab study"
Authors: K. Yang, et al.