Spicy food consumption is associated with adiposity measures among half a million Chinese people: the China Kadoorie Biobank study

Abstract

Background: Few animal experiments and volunteer-based intervention studies have showed a controversial effect of spicy foods on weight management; however, information is scant on the association between spicy food intake and obesity. This study aims to examine the impact of spicy food on quantitative adiposity measures in the Chinese population; a population with a low prevalence of general obesity, but a high prevalence of central obesity.

Methods: A total of 434,556 adults (255,094 females), aged 30-79 years, were included from the China Kadoorie Biobank (CKB) study. Information on spicy food intake was obtained using a questionnaire survey. Body mass index (BMI), percentage body fat (BF%), waist circumference (WC), and WC/height ratio (WHtR) were analyzed as continuous variables.

Results: The prevalence of daily spicy food eating was 30.4% in males and 30.0% in females, with dramatically geographic diversity (ranging from 99.4% in Hunan to 2.7% in Zhejiang). The covariates-adjusted BMI, BF%, WC, and WHtR significantly increased with increasing frequency, strength, and duration of spicy food eating regardless of gender (p < 0.001). Among regular spicy food consumers, strength of spicy food eating showed significant and positive association with all adiposity measures in both genders (except for BF% in males). Compared with non-consumers, daily spicy food eating was significantly associated with an increase of 0.44 and 0.51 of BMI (kg/m2), 0.79 and 1.01 of BF%, 1.4 and 1.0 of WC (cm), and 0.008 and 0.006 of WHtR in males and females, respectively. In stratified analyses of 18 consecutive BMI subgroups, a significantly increasing trend in the effect of daily spicy food eating on WC and WHtR with increasing BMI was noted in males; whereas a decreasing trend was seen in females.

Conclusions: The data indicate that spicy food intake is a risk factor for obesity in Chinese adult population, especially for central obesity in males. Further studies are needed to elucidate the mechanisms underlying this association.

Figure 1

Frequency of spicy food eating of participants in 10 survey sites of the CKB study.

Figure 2

Site-specific and overall effect of daily spicy food eating on BMI (a), BF% (b), WC (c) and WHtR (d) by gender groups. Each closed square represents the point estimate of the regression coefficient, and the horizontal bar represents its 95% confidence interval (CI), which was estimated by using multiple linear regression models. Adjustment was made for age, study sites, education, alcohol and tobacco use, physical activity, alcohol drinking, smoking and survey site. The size of the square is proportional to the weight calculated by using the DerSimonian and Laird method. The overall point estimates, calculated in random effect models, are represented by dotted lines and closed diamonds, and the horizontal bar represents its 95% CI. BMI, body mass index; BF%, percentage body fat; WC, waist circumference; WHtR, WC-to-height ratio.

Figure 3

Standardized regression coefficients of daily spicy food eating for adiposity variables by 18 BMI groups in males and females. Absolute values of standardized regression coefficients ≥ 0.0338 in males and ≥0.0280 in females were significant (p < 0.05) for a; ≥ 0.0311 in males and ≥0.0311 in females for b; ≥ 0.0306 in males and ≥0.0216 in females for c. BMI, body mass index; BF%, percentage body fat; WC, waist circumference; WHtR, WC-to-height ratio.