No abstract

The authors investigate the impact of advertising beauty images on female preadolescents and adolescents. An experiment using 4th, 8th, and 12th graders demonstrated that exposure to advertising with highly attractive models raises comparison standards for physical attractiveness, but does not affect self‐perceptions of physical attractiveness. The findings also suggest that the tendency of female pre‐adolescents and adolescents to compare themselves to models in ads increases with age, and this tendency is greater for those with lower self‐perceptions of physical attractiveness and/or self‐esteem. © 1993 John Wiley & Sons, Inc.

Infection with intestinal helminths results in immunological changes that influence the odds of comorbid infections, and might also affect fecundity by inducing immunological states supportive of conception and pregnancy. Here we investigate associations between intestinal helminths and fertility in human females, utilizing nine years of longitudinal data from 986 Bolivian forger-horticulturalists, experiencing natural fertility and a 70% helminth prevalence. We find that different species of helminth are associated with opposing effects on fecundity. Infection with roundworm (Ascaris lumbricoides) is associated with earlier first births and shortened interbirth intervals, while infection with hookworm is associated with delayed first pregnancy and extended interbirth intervals. Thus, helminths may have important, and sometimes contradictory effects on human fertility, reflecting the physiological and immunological consequences of infection with particular species.

Background Traditional diets are often credited for the robust cardiometabolic health of subsistence populations. Yet, rural subsistence populations are undergoing nutrition transitions that have been linked to the increase in chronic noncommunicable diseases. Few studies have presented detailed dietary estimates in transitioning populations. Objectives We aimed to 1) characterize and compare dietary profiles of 2 neighboring subsistence populations in Bolivia who vary in market integration and 2) identify dietary factors contributing to low cardiovascular disease risk. Design We used a mixed longitudinal design to estimate nutrient intake via 24-h recall and dietary questionnaires among 1299 Tsimane (aged 30–91 y) and 229 Moseten (aged 30–84 y) men and women. We constructed population-level estimates of energy intake, dietary diversity, and nutrient shortfalls and analyzed dietary changes over time and space using multilevel models. Last, we compared Tsimane and Moseten dietary profiles with those of Americans (NHANES). Results The Tsimane diet was characterized by high energy (2422–2736 kcal/d), carbohydrate (376–423 g/d), and protein (119–139 g/d) intakes; low fat intake (40–46 g/d); and low dietary diversity relative to the average US diet. Most calories (64%) were derived from complex carbohydrates. Total energy and carbohydrate intake increased significantly during the 5-y study, particularly in villages near market towns. Tsimane consumption of food additives (lard, oil, sugar, salt) increased significantly [sugar (15.8 g ⋅ person−1 ⋅ d−1) and oil (4.9 mL ⋅ person−1 ⋅ d−1)] between 2010 and 2015. The more-acculturated Moseten consumed substantially more sugar (by 343%) and oil (by 535%) than the Tsimane. Conclusions A high-energy diet rich in complex carbohydrates is associated with low cardiovascular disease risk when coupled with a physically active lifestyle. A transition away from a high-fiber and low-fat, low-salt, and low-processed-sugar diet is a salient health risk for transitioning populations. Evidence of a nutrition transition in Bolivia parallels trends of increasing body fat and body mass index, which suggests that a low prevalence of cardiovascular disease may not persist.

Breast milk fatty acid (FA) composition varies greatly among individual women, including in percentages of the long-chain polyunsaturated FAs (LCPUFA) 20:4n-6 (arachidonic acid, AA) and 22:6n-3 (docosahexaenoic acid, DHA), which are important for infant neurological development. It has been suggested that owing to wide variation in milk LCPUFA and low DHA in Western diets, standards of milk FA composition should be derived from populations consuming traditional diets. We collected breast milk samples from Tsimane women at varying lactational stages (6–82 weeks). The Tsimane are an indigenous, natural fertility, subsistence-level population living in Amazonia Bolivia. Tsimane samples were matched by lactational stage to samples from a US milk bank, and analysed concurrently for FA composition by gas-liquid chromatography. We compared milk FA composition between Tsimane (n = 35) and US (n = 35) mothers, focusing on differences in LCPUFA percentages that may be due to population-typical dietary patterns. Per total FAs, the percentages of AA, DHA, total n-3 and total n-6 LCPUFA were significantly higher among Tsimane mothers. Mean percentages of 18:2n-6 (linoleic acid) and trans FAs were significantly higher among US mothers. Tsimane mothers’ higher milk n-3 and n-6 LCPUFA percentages may be due to their regular consumption of wild game and freshwater fish, as well as comparatively lower intakes of processed foods and oils that may interfere with LCPUFA synthesis.