Weight loss theory debunked – exercise a bigger weapon against obesity than diet
To lose weight, work up a sweat: exercise has a significant impact on fatty tissue, metabolism and gut microbes, a new study finds
In the debate over the roles of exercise and diet in weight loss, one argument is that exercise does not play a significant role as it increases appetite, resulting in greater food intake, and potentially reduces activity through the day. A University of Missouri study proves this theory wrong, showing that exercise has significant impact on fat tissue, metabolism and gut microbes.
Researchers divided young rats prone to obesity into three groups. All three groups were fed a high-fat diet. Two of the groups were sedentary while the third group was able to exercise using running wheels. Of the two sedentary groups, one was allowed to eat as much of the high-fat food as they wanted, while the other group were fed controlled portions of the food in order to match the weight reduction caused by exercise. The exercising rats were allowed to eat as much as they wanted.
Several weeks later, the sedentary rats with unlimited food access were unsurprisingly obese. Notably, the exercising rats were metabolically healthier and developed different gut microbes than both of the sedentary groups, despite eating the exact same amount of food as the sedentary group with unlimited food access. Overall, the exercising rats had higher metabolic rates, were more active even when not running on their wheels and experienced shifts in their gut microbes, perhaps putting them in a better position to avoid future weight gain compared to the other groups.
Early introduction of allergenic foods reduces risk of food sensitisation
Children who have a diet that includes cow’s milk products, eggs and peanuts before the age of one are less likely to develop sensitisation to the corresponding foods, according to new research by Canada’s McMaster University presented at the international conference of the American Thoracic Society.
Early introduction of eggs appeared to be especially beneficial, as it decreased the risk of sensitisation to any of the three tested foods. The study included data from 1,421 children.
“The clinical implications of our findings are that early introduction of allergenic foods [eggs, cow’s milk products, and peanuts] before age one should be encouraged and is better than food avoidance for reducing the risk of food sensitisation,” says lead investigator Maxwell Tran. “Sensitisation is not the same as allergy, but it is an important step on the pathway.”
The results of the study reinforce a shift in thinking from delayed food introduction to earlier food introduction for allergy prevention. “Many guidelines around the world are now reflecting this shift, with the recommendation of food introduction before six months of age,” says Tran.
ADHD may emerge after childhood for some people, according to new study
While it is well established that childhood attention-deficit/hyperactivity disorder (ADHD) may continue into adulthood, new research by King’s College London suggests that for some people the disorder does not emerge until after childhood.
ADHD is a developmental disorder marked by inattention, hyperactivity and impulsivity and is one of the most common behavioural disorders in children. Published in JAMA Psychiatry, the study looked at 2,200 British twins whose symptoms of childhood ADHD were measured at the ages of five, seven, 10 and 12 through mother and teacher reports. Young adults were interviewed at the age of 18 to assess ADHD symptoms and any associated impairments, as well as the existence of other mental health disorders. Nearly 70 per cent of the young adults with ADHD in the study did not meet criteria for the disorder at any of the childhood assessments.
Adults with this “late-onset” ADHD had high levels of symptoms, impairment and other mental health disorders. Findings from this British cohort are confirmed by evidence for adult-onset ADHD in Brazil and New Zealand. The British researchers also found adult ADHD, which occurs in approximately 4 per cent of adults, was less heritable than childhood ADHD. And having a twin with childhood ADHD did not place individuals at a higher risk of developing late-onset ADHD.