Jonathan Ck Wells

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Physical inactivity is an important contributor to non-communicable diseases in countries of high income, and increasingly so in those of low and middle income. Understanding why people are physically active or inactive contributes to evidence-based planning of public health interventions, because effective programmes will target factors known to cause(More)
BACKGROUND Objective methods can improve accuracy of physical activity measurement in field studies but uncertainties remain about their use. METHODS Children age 11 years from the Avon Longitudinal Study of Parents and Children (ALSPAC), were asked to wear a uni-axial accelerometer (MTI Actigraph) for 7 days. RESULTS Of 7159 children who attended for(More)
BACKGROUND Previous studies have been unable to characterise the association between physical activity and obesity, possibly because most relied on inaccurate measures of physical activity and obesity. METHODS AND FINDINGS We carried out a cross sectional analysis on 5,500 12-year-old children enrolled in the Avon Longitudinal Study of Parents and(More)
Human growth in early life has major implications for fitness. During this period, the mother regulates the growth of her offspring through placental nutrition and lactation. However, parent-offspring conflict theory predicts that offspring are selected to demand more resources than the mother is selected to provide. This general issue has prompted the(More)
CONTEXT Rapid postnatal weight gain has been associated with subsequent increased childhood adiposity. However, the contribution of rapid weight gain during specific infancy periods is not clear. OBJECTIVE We aimed to determine which periods of infancy weight gain are related to childhood adiposity and also to age at menarche in UK girls. DESIGN,(More)
Recent measurements at a cabled sea-floor node in 15 meters of water off the coast of New Jersey suggest that Langmuir supercells, Langmuir circulations that achieve vertical scales equal to the water depth under extended storms, are an important mechanism for major sediment resuspension events on the extensive shallow shelves off the eastern U.S. coast.(More)
OBJECTIVE Maternal smoking during pregnancy has been shown to be associated with obesity in the offspring, but findings have been based mainly on BMI, which is derived from height and weight. This study examined the association between maternal and partner smoking during pregnancy and offspring total fat, truncal fat, and lean mass in childhood. RESEARCH(More)
Pelotas is a city in the extreme south of Brazil, near the border of Uruguay, with 214 000 urban inhabitants in 1982. At the time, we were assistant professors, each working in one of the two medical schools in the city, and both undergoing post-graduate training at the University of London. We were inspired by the findings of the British perinatal study,(More)
BACKGROUND Dual-energy X-ray absorptiometry (DXA) is widely used to assess body composition in research and clinical practice. Several studies have evaluated its accuracy in healthy persons; however, little attention has been directed to the same issue in patients. OBJECTIVE The objective was to compare the accuracy of the Lunar Prodigy DXA for(More)
Medical research is increasingly focusing on the contribution of nutritional programming to disease in later life. Programming is a process whereby a stimulus during a critical window of time permanently affects subsequent structure, function or developmental schedule of the organism. The thrifty phenotype hypothesis is widely used to interpret such(More)