The incidence of colorectal cancer (CRC) is dramatically higher in African Americans (AAs) than in Native Africans (NAs) (60:100,000 vs. <1:100,000) and slightly higher than in Caucasian Americans (CAs). To explore whether the difference could be explained by interactions between diet and colonic bacterial flora, we compared randomly selected samples of healthy 50- to 65-y-old AAs (n = 17) with NAs (n = 18) and CAs (n = 17). Diet was measured by 3-d recall, and colonic metabolism by breath hydrogen and methane responses to oral lactulose. Fecal samples were cultured for 7-alpha dehydroxylating bacteria and Lactobacillus plantarum. Colonoscopic mucosal biopsies were taken to measure proliferation rates. In comparison with NAs, AAs consumed more (P < 0.01) protein (94 +/- 9.3 vs. 58 +/- 4.1 g/d) and fat (114 +/- 11.2 vs. 38 +/- 3.0 g/d), meat, saturated fat, and cholesterol. However, they also consumed more (P < 0.05) calcium, vitamin A, and vitamin C, and fiber intake was the same. Breath hydrogen was higher (P < 0.0001) and methane lower in AAs, and fecal colony counts of 7-alpha dehydroxylating bacteria were higher and of Lactobacilli were lower. Colonic crypt cell proliferation rates were dramatically higher in AAs (21.8 +/- 1.1% vs. 3.2 +/- 0.8% labeling, P < 0.0001). In conclusion, the higher CRC risk and mucosal proliferation rates in AAs than in NAs were associated with higher dietary intakes of animal products and higher colonic populations of potentially toxic hydrogen and secondary bile-salt-producing bacteria. This supports our hypothesis that CRC risk is determined by interactions between the external (dietary) and internal (bacterial) environments.

Obesity is a public health problem, affecting more than half of the global population. Perceptions and beliefs play a significant role in preventing and managing overweight and obesity. Thus, the paper explores own perception of overweight and obesity on personal health among South African adults. This was a qualitative study in which the participants (n = 24) were interviewed in-depth on their perception of obesity and health. Thematic analysis was used in data assessment. The results revealed four main themes: perceived causes of obesity, self-perception of being obese, perception of obesity, health, and cultural beliefs. Environmental and personal factors were perceived as the leading cause of overweight and obesity. The findings further showed that body weight preference was personal and differed from individual to individual. The study provided insight into perceptions of obesity from individuals’ perspectives. The misperceptions of overweight and obesity are helpful in the design of impactful intervention programmes that can be used to prevent and manage obesity in South Africa.

Obesity has become a serious public health problem worldwide and is linked to an increased risk of non-communicable diseases (NCDs). Poor self-perception of body weight is postulated to play a negative role in curbing increased rates of obesity. This study investigated the views of own body weight and perceived risk of developing NCDs in South African adults. This was a community-based quantitative study. Descriptive statistics were used, and logistic regression analysis was conducted on the data. A total of 1050 respondents took part in the study. Of the 161 respondents who perceived themselves to be normal weight, 98.8% (n = 159) misperceived their body weight. The majority of respondents (>90%) who were overweight according to the calculated BMI perceived no risk of developing obesity-related diseases. Most of the respondents, 46% (n = 253), believed that body weight was influenced by heredity. The method used for weight loss by 57% (n = 173) of the respondents was exercising at home. There was a statistically significant association between Body Mass Index (BMI), employment status, risk of developing diabetes, and body weight misperception (p < 0.05). Misperception of body weight was common among the study respondents and may influence weight control intervention strategies. Health promotion targeting personal behaviour, such as body weight self-perception, is crucial in supporting targeted strategies to address obesity in South Africa.