South Africa (SA) is undergoing a rapid epidemiological transition and has the highest prevalence of obesity in subSaharan Africa (SSA), with black women being the most affected (obesity prevalence 31.8%). Although genetic factors are important, socio-cultural, environmental and behavioural factors, as well as the influence of socio-economic status, more likely explain the high prevalence of obesity in black SA women. This review examines these determinants in black SA women, and compares them to their white counterparts, black SA men, and where appropriate, to women from SSA. Specifically this review focuses on environmental factors influencing obesity, the influence of urbanisation, as well as the interaction with socio-cultural and socio-economic factors. In addition, the role of maternal and early life factors and cultural aspects relating to body image are discussed. This information can be used to guide public health interventions aimed at reducing obesity in black SA women.

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Summary Studies have shown bidirectional relationships between short‐ or long‐sleep duration and risk for obesity, non‐communicable diseases, all‐cause mortality and cardiovascular disease mortality. Increasing sleep duration may be an appropriate strategy to reduce cardiometabolic risk in short‐sleeping individuals. The aim is to review the effects of sleep extension interventions on cardiometabolic risk in adults. The PubMed and Scopus databases were searched for relevant, English, peer‐reviewed scientific publications (until August 2018). Seven studies that aimed to increase sleep duration in adults by any sleep extension intervention and described at least one cardiometabolic risk factor were included. These studies had a combined sample size of 138 participants who were either healthy (n = 14), healthy short‐sleeping (n = 92), overweight short‐sleeping (n = 10), or pre‐ or hypertensive short‐sleeping (n = 22) individuals. The durations of the sleep extension interventions ranged from 3 days to 6 weeks, and all successfully increased total sleep time by between 21 and 177 min. Sleep extension was associated with improved direct and indirect measures of insulin sensitivity, decreased leptin and peptide tyrosine‐tyrosine, and reductions in overall appetite, desire for sweet and salty foods, intake of daily free sugar, and percentage of daily caloric intake from protein. This review provides preliminary evidence for a role for sleep extension to improve cardiometabolic outcomes and directive towards future studies in the field of cardiometabolic health and sleep.

A growing body of evidence suggests that capsaicin ingestion may lead to desirable metabolic outcomes; however, the results in humans are equivocal. Whether or not benefits may be gained from ingestion of capsaicin via a commercially available meal has not been determined. The objectives of this randomised, cross-over intervention study were to compare the 2 h postprandial effects of a standard commercially prepared meal containing chilli (HOT, 5·82 mg total capsaicinoids) with a similar meal with no chilli (CON, <1·0 mg total capsaicinoids) on resting energy expenditure, plasma insulin, glucose, serum high sensitivity C-reactive protein (hs-CRP) concentrations, core body temperature and forearm microvascular reactivity responses in overweight individuals. A total of thirty-four apparently healthy individuals (sixteen men and eighteen women) between 18 and 50 years of age, with a BMI >25 kg/m 2 and a waist circumference >94 cm (men) or 80 cm (women), were studied. Participants had normal glucose tolerance and were accustomed, but were not regular chilli eaters. A paired t test indicated that insulin AUC was smaller following the HOT meal (P = 0·002). Similarly, there was a tendency for glucose AUC to be reduced following the HOT meal (P = 0·056). No discernable effects of the HOT meal were observed on metabolic rate, core temperature, hs-CRP concentrations and endothelial-dependent microvascular reactivity. The results from this study indicate that a standard restaurant meal containing a relatively small dose of capsaicin delivered via African bird's eye chilli, which is currently available to the public, results in lower postprandial insulin concentrations in overweight individuals, compared with the same meal without chilli.