Obesity continues to a major problem worldwide and it is associated with a range of metabolic disorders. Definitions of obesity vary, although it is generally accepted that obesity refers to the condition where excess body fat accumulates to an extent that it may have a negative effect on health.
There are different causes of obesity and the condition is not only linked to poor diet and insufficient exercise (such as eating excessive amounts of cheap high-calorie food and spending a lot of time sitting down at desk), for there are genetic issues to consider as well.
According to the University of Virginia there are differences in fat storage and formation between men and women, and this is influenced by different genes found in fat tissue. Furthermore, some of those genes identified are connected with conditions like type 2 diabetes and cardiovascular disease.
The reason for highlighting the genetic basis is to indicate that the causes of obesity and strategies of address obesity are more complicated than sometimes portrayed. This does not negate the danger surrounding obesity, as three new strands of research show, including one of topical interest in relation to the coronavirus pandemic.
Nutrition and childhood development
Part of the new sets of data relating to obesity and nutrition includes a study which looks at the impact upon children. Taking a longitudinal look, a new analysis considers height and weight of school-aged children and adolescents across the world.
That diet is important matches other research, albeit from a different perspective, such as one study that finds that a healthy quality Mediterranean-like diet partially modifies the association between obesity and cardiovascular mortality.
This study, which comes from Imperial College London, draws upon health information and other metrics relating to 65 million children. The children were aged between five to 19 years old, and the findings are collected from 193 countries.
This analysis shows that school-aged children’s’ height and weight, serving as indicators of their health and quality of their diet, vary enormously around the world. The analysis reveals a 20 centimeter difference between 19-year-olds in the tallest and shortest nations. The key variable is with childhood nutrition, including a lack of quality food. This important factor is associated with stunted growth and a rise in childhood obesity.
It also follows that the lifestyle of women with obesity during pregnancy can lead to long-term cardiovascular benefits for their children. If exercise is not regularly performed, the reverse can occur and children from obese mothers carry a risk of being less healthy and also becoming prone to developing obesity themselves.
The findings appear in the medical journal The Lancet, titled “Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants.”
At the other end of the age scale, severely overweight people are less likely to be able to re-wire their brains and find new neural pathways. This is something of importance in relation to stroke recovery. This finding appears in the journal Brain Science (“Obesity is Associated with Reduced Plasticity of the Human Motor Cortex”).
Too much sugar
A related area of research is linked to sugar in the diet. A study, looking at an animal model, has discovered that mice fed diets high in sugar developed worse forms of colitis than mice fed a standard diet.
Colitis is a form of inflammatory bowel disease. To explore the effects further, the researchers from UT Southwestern Medical Center examined the large intestines of the mice and discovered more of the bacteria that can damage the gut’s protective mucus layer to be present.
Importantly, the study pointed to sugar, such as the type of glucose found in high fructose corn syrup (used by parts of the food industry since the 1960s0 as the mist significant contributor to the effects.
The researchers have indicated that effect seen with mice can be extrapolated to humans, and this should act as some form of warning for a diet too rich in sugar.
The research is published in the journal Science Translational Medicine, titled “Dietary simple sugars alter microbial ecology in the gut and promote colitis in mice.”
Obesity and coronavirus risk
An individual’s health is important when considering coronavirus risk. A new study finds that factors inherent to obesity could increase vulnerability to COVID-19. Correlations in many countries exist between obesity and COVID-19 deaths.
In particular, inflammation in the lungs, when combined with high viral loads of the coronavirus, appears to create ‘a perfect storm’ for obese patients with COVID-19. Fat has high amounts of ACE2 receptors. These receptors serve as the entryways for the SARS-CoV-2 virus into the cells of the lungs.
Another concern is with the higher overall inflammatory state that accompanies obesity, and which primes many tissues to show a poor response to infection.
The outcome from the research is that medications used to lower inflammation in the lungs are beneficial to obese patients who have coronavirus. This may lead to a new medical intervention.
The research appears in eLife, titled “Obesity and diabetes as comorbidities for COVID-19: Underlying mechanisms and the role of viral–bacterial interactions.”
Essential Science
This article forms part of Digital Journal’s long-running Essential Science series, where new research relating to wider science stories of interest are presented on a weekly basis.
Last week we focused on coronavirus, considering why scientists are concenred over the issue of why some people become sicker than others when infected with the coronavirus. The answers may lie in with vitamin D levels.
The week before, our topic was global heating. We learned that as climate change continues to cause the average temperature around the planet to rise, staying cooler in what are increasingly set to be long, dry, and hot summers is a challenge that humanity needs to face. We examined three solutions for keeping cooler.
