Steve N. Blair

Changing the Endpoints for Determining Effective Obesity Management

Health authorities worldwide recommend weight loss as a primary endpoint for effective obesity management. Despite a growing public awareness of the importance of weight loss and the spending of billions of dollars by Americans in attempts to lose weight, obesity prevalence continues to rise. In this report we argue that effective obesity management in todays environment will require a shift in focus from weight loss as the primary endpoint, to improvements in the causal behaviors; diet and exercise/physical activity (PA). We reason that increases in PA combined with a balanced diet are associated with improvement in many of the intermediate risk factors including cardiorespiratory fitness (CRF) associated with obesity despite minimal or no weight loss. Consistent with this notion, we suggest that a focus on healthy behaviors for the prevention of additional weight gain may be an effective way of managing obesity in the short term.

Myopia and later physical activity in adolescence: a prospective study

Objectives: To investigate associations between objectively measured physical activity (PA) and myopia in children. Methods: Children from the Avon Longitudinal Study of Parents and Children (ALSPAC) were asked to wear a uniaxial accelerometer for 7 days. Measures of counts per minute (cpm), minutes spent in moderate to vigorous activity (MVPA) and minutes of sedentary behaviour (msed) were derived from the accelerometer worn at age 12. Children were also examined, at age 10, using an autorefractor to estimate myopia. Social and parental factors were collected from pregnancy and physical measures of the child were recorded at age 12. Results: 4880 children had valid PA and autorefraction data. In minimally adjusted models (age and gender) myopic children were less active than the other children: β = −49.9 cpm (95% CI −73.5 to −26.4, p = <0.001). The myopic group spent less time in MVPA than the other children: β = −3.2 minutes MVPA (95% CI −5.2 to −1.1, p = 0.003) and more time sedentary: β = 15.8 minutes (95% CI 5.8 to 25.8, p = 0.002). The effect sizes were attenuated by adjustment for social and behavioural confounders although myopia status in the better (less myopic on autorefraction) eye remained strongly associated with cpm and MVPA but less so for sedentary behaviour: β = −36.8 cpm (95% CI –67.8 to −5.8, p = 0.02), β = −2.7 MVPA (95% CI −5.3 to −0.1, p = 0.04), β = 10.1 msed (95% CI –2.9 to 23.1, p = 0.13). Conclusion: Myopic children may be more at risk of having lower levels of PA than their non-myopic peers, although the difference was modest.

Individuals with obesity but no other metabolic risk factors are not at significantly elevated all-cause mortality risk in men and women: Metabolic healthy obesity and mortality risk

Studies have examined mortality risk for metabolically healthy obesity, defined as zero or one metabolic risk factors but not as zero risk factors. Thus, we sought to determine the independent mortality risk associated with obesity or elevated glucose, blood pressure or lipids in isolation or clustered together. The sample included 54 089 men and women from five cohort studies (follow‐up = 12.8 ± 7.2 years and 4864 [9.0%] deaths). Individuals were categorized as having obesity or elevated glucose, blood pressure or lipids alone or clustered with obesity or another metabolic factor. In our study sample, 6% of individuals presented with obesity but no other metabolic abnormalities. General obesity (hazard ratios [HR], 95% CI = 1.10, 0.8–1.6) and abdominal obesity (HR = 1.24, 0.9–1.7) in the absence of metabolic risk factors were not associated with mortality risk compared to lean individuals. Conversely, diabetes, hypertension and dyslipidaemia in isolation were significantly associated with mortality risk (HR range = 1.17–1.94, P < 0.05). However, when using traditional approaches, obesity (HR = 1.12, 1.02–1.23) is independently associated with mortality risk after statistical adjustment for the other metabolic risk factors. Similarly, metabolically healthy obesity, when defined as zero or one risk factor, is also associated with increased mortality risk (HR = 1.15, 1.01–1.32) as compared to lean healthy individuals. Obesity in the absence of metabolic abnormalities may not be associated with higher risk for all‐cause mortality compared to lean healthy individuals. Conversely, elevation of even a single metabolic risk factor is associated with increased mortality risk.