Bright light for weight loss: results of a controlled crossover trial.

OBJECTIVE: To investigate whether bright light treatment can reduce body mass in overweight subjects irrespective of their seasonal (= light) dependence. METHODS: A crossover, placebo-controlled, randomized clinical trial was performed between November and April in Novosibirsk, Russia (55° N). The trial comprised a 3-week in-home session of morning bright light treatment using a device of light-emitting diodes and a 3-week placebo session by means of a deactivated ion generator, separated by an off-protocol period of at least 23 days. The number of placebo and light sessions was matched with respect to season. Data were obtained from 34 overweight women, aged 20-54 years, 10 were seasonal-dependent according to the Seasonal Pattern Assessment Questionnaire. Weekly measures included body weight, percentage body fat by bioimpedancemetry, and subjective scores (appetite, mood, energy levels). RESULTS: Motivation and expectation towards weight loss were similar for the two intervention sessions. With light, compared to the placebo session, weight did not reduce significantly, but percentage fat, fat mass, and appetite were significantly lower (average fat reduction 0.35 kg). The latter two results remained significant after excluding seasonal-dependent subjects from the analysis. Irrespective of the type of intervention, seasonal-dependent subjects had greater weight and fat mass changes during treatment (decline p < 0.036) or between sessions (regain p < 0.003). Photoperiod (p = 0.0041), air temperature to a lesser extent (p = 0.012), but not sunshine (p = 0.29) was associated with the weight change (greater weight reduction if the second session was in spring). CONCLUSION: Morning bright light treatment reduces body fat and appetite in overweight women and may be included in weight control programs.

Dimensions of health and social structure in the early intermediate period cemetery at Villa El Salvador, Peru.

This paper examines relationships between the social structure of a community and the health of its members, based on analysis of human skeletal remains (N = 64) from Villa El Salvador XII (100 BC-AD 100), a prehistoric cemetery located in the lower Lurín Valley, Peru. The ambiguity of social status as conventionally inferred from archaeological context is among the principal complicating factors in such an inquiry. We use multidimensional scaling of skeletal markers to identify the presence of patterned health-based heterogeneity in our sample, without making a priori assumptions about underlying social structure at Villa El Salvador. This procedure situates every skeleton relative to all others in the sample on the basis of multiple health markers, eliciting health groups. Once recognized, the relevance of those groups to social structure can be evaluated by comparison with a broad range of presumptive archaeological status indicators. We test the hypothesis that the distribution of stress indicators in human skeletons covaries with archaeological indicators of social differentiation. Based on multivariate analysis of skeletal indicators, we conclude that the cemetery at Villa El Salvador was utilized by two social groups with different geographic affinities: one of local coastal origin, and the other probably from the upper Lurín Valley or adjacent higher altitudes. These groups differ in skeletal characteristics related to childhood health, probably reflecting systematic contrasts in the growth environments of the studied individuals. This same division is independently supported by the distribution of cranial deformation, a possible marker of ethnicity. We also document some inequality in the distribution of labor among male individuals, as reflected by the relative advancement of degenerative joint disease, and congruent with differences in the number and quality of associated funerary offerings.

Diet and health changes at the end of the Chinese neolithic: the Yangshao/Longshan transition in Shaanxi province.

In this paper we discuss diet and health changes of millet agriculturists in Northern China, Shaanxi province, during the period 7,000-4,000 BP. An episode of intensive climatic oscillations that preceded the onset of colder climate circa the fifth millennium BP divides the period (Shi et al. [1993] Global Planet. Change 7:219-233). The onset of the cooler climate marks the decline of the egalitarian society of Yangshao and the rise of the chiefdom-like society of Longshan. Skeletal materials from the two sites of Beiliu and Jiangzhai are from the earlier phases of Yangshao culture (7,000-6,000 BP), while remains from the Shijia site were excavated from the terminal phase of Yangshao culture (6,000-5,000 BP), a phase that would be expected to show adjustments to strong climatic fluctuations. Human remains from the Longshan culture (5,000-4,000, BP) were found at the Kangjia site. In order to investigate whether the trajectory of diet and health changes persisted beyond the Longshan, a skeletal sample from the Xicun site of the Western Zhao Dynastic period (3,800-2,200 BP) is included in our analyses. All Yangshao sites in our study are characterized by low frequencies of anemia and carious lesions. Some subsistence changes probably occurred during the later phase of Yangshao culture that resulted in elevated masticatory stress and occlusal macrowear among the Shijia people. However, deterioration of community health did not begin until the Longshan, when increased occurrence of porotic hyperostosis and caries is accompanied by decreased adult stature. The transition to softer, more extensively processed food during Longshan is evident in decreased rates of occlusal wear. Increased population density and diminished food values were most likely responsible for these changes. Poor health persisted into the subsequent Dynastic period of Western Zhao.