A glass of water a day keeps obesity away?
Drinking 500ml of water half an hour before eating meals may help obese adults lose weight. A study conducted at the University of Birmingham on 84 obese adults showed that this simple intervention could be profoundly beneficial. The group was randomly split into two, and both were given a weight management consultation, to discuss how best to adapt lifestyle and behaviour, in order to promote weight loss. 41 were asked to “preload” with water before eating, whilst the others were told to imagine their stomach was full.
The participants were monitored over a 12 week period, and those that were asked to drink water before their main meal lost, on average, 1.3kg more than those in the control group. Those who preloaded 3 times a day lost 4.3kg! The intervention was simple and was shown to be effective at follow-up. We must bear in mind though that it was not only filling up on water before meals that resulted in weight loss, each participant was given lifestyle advice. The researchers hope to continue their research on a larger population in the future.
Read MoreBad news for first born sisters…
Older sisters are more likely to be overweight and obese when compared to their younger siblings. According to a large study performed on 13, 406 Swedish sister pairs. The results corroborate with previous studies that found older brothers to be both, heavier, and taller, than their younger siblings. The study showed that at birth, firstborns weighed a little less than the second born sisters, however their BMI was around 2.4% higher during their first 3 months of pregnancy.
Overall it was found that firstborn women were 29% more likely to be overweight, and 40% more likely to be obese during their mid-20s, furthermore they were an average of 1.2mm taller. Sisters with a high number of siblings were also more likely to be shorter and the researchers hypothesised that this could be due to a phenomenon known as ‘resource dilution’ – the idea that parental resources are spread more thinly across a higher number of children.
It was unclear why older sisters seemed to be heavier, however the researchers hypothesised that changes in the womb after the first pregnancy could be a potential cause. It is possible that during the first pregnancy, blood vessels are narrower in the placenta, limiting flow. The body then adapts to this to store more fat and glucose. For subsequent pregnancies the blood flow is altered to stop this from happening. Although the findings confirm the results in other studies involving men, more research is needed to see whether there is an associated increase in metabolic risk in first born women.
Read MoreDoes a feeling of reward cause obesity?
A French team have examined the role of pleasure when compared to that of energy needs in food intake. The study was performed on a group of mice and considered the activity of neurones that regulate feeding behaviours, known as NPY/AgRP. These are activated in periods of fasting and promote food intake. They found that these neurones become dispensable when a highly palatable diet is chosen; instead the hedonic circuitry in the brain drives the feeding behaviours. However when food is not palatable, it is the AgRP neurones that drive feeding in response to the body’s metabolic needs.
Using these findings it was shown that animals with compromised AgRP neurone activity could be more prone to comfort eating as they are more likely to consume palatable food due to stress. The mice with compromised AgRP neurones were also more sensitive to external factors, such as stress, they were therefore very good models for comfort eating.
A continued exposure to palatable foods, many of which are energy-rich could alter NPY/AgRP circuitry and cause them to become desensitised, leading to the reward circuit taking over. Overall, these results shed more light on the energy balance mechanisms controlled by NPY/AgRP and highlights how the reward circuitry interacts with it and may explain why people can’t seem to avoid eating the wrong foods!
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