Are junk food and fizzy drinks really to blame for obesity?
Whilst junk food and fizzy drinks have often been portrayed as the villains in the fight against obesity, they may not be the leading causes of obesity according to a new study published in Obesity Science & Practice. Researchers reviewed a nationally (according to the USA) representative group of adults and found that consumption of fast food, fizzy drinks and sweets was not linked to BMI for 95% of the population. The study used data from the Centers for Disease Control’s National Health and Nutrition Examination Survey for 2007-08, which contained over 5,000 participants. They looked at anthropometric body measurements, including height and weight, and then combined these findings with questionnaires about diet. There was no significant difference in consumption of these foods between overweight and normal weight individuals. However they did not take into account differences between those with increased waist circumferences and normal weights
These findings led the team to believe that, whilst it is not recommended to over-indulge in these foods, they are not the overwhelming contributors to obesity. Dr David Just, a co-author for the study, suggested that campaigns that demonise certain foods may not be doing as much good as we’d thought, and it is behaviours and overall diet that need to be targeted in order to effectively curb obesity.
Read MoreIs abdominal fat more dangerous than overall BMI?
Central obesity in normal weight individuals means they are at a greater risk of complications than those that are overweight without excess abdominal fat. This is a conclusion from a study conducted in Minnesota, USA. The study looked at 14 years of data from over 15,000 participants in the Third National Health Nutrition Examination Survey which ran from 1988-1994. Central obesity was defined as a waist-hip ratio of ≥0.85 in women and ≥0.9 in men (this is according to the WHO criteria). They found that normal-weight participants with central obesity had worse long-term survival rates than their counterparts with normal fat distribution, regardless of the latters’ BMI. This was mostly due to increased risks for cardiovascular disease and diabetes, and an overall increased risk of total mortality.
Dr Lopez-Jimenez, lead author of the study explained that, with these results, measurements of waist-hip ratio should be included as part of general medical examinations, to ensure that the possible increased risk was not overlooked. This advice goes against current obesity management guidelines from the American Heart Association and the Obesity Society, who both say that waist measurements should only be taken in those who are obese. It will be interesting to see if changes are made to these guidelines as a result of this study.
Read More1 cm on the waist = higher risk of colon cancer
There is an increased risk of developing large bowel cancer for every 1cm gained on the waist. This comes after experts released compelling evidence at the United European Gastroenterology Week conference in Barcelona. Professor John Mathers, from Newcastle University, revealed that the risk of colorectal cancer (CRC) was increased by nearly 60% in men whose waist circumference had increased by 10cm over a 10 year period. He also claimed that this increased cancer risk may be due to the fact that there is persistent inflammation in people with visceral obesity.
Prof. Mathers said that this evidence shows that improved lifestyle, better dietary choices, and being more active, will not only help fight obesity, but also the risks that being obese carries, such as the increased bowel cancer risk. He conceded that the area requires more study, so that we can find out whether other types of cancer are affected, and also what the possible long-term interventions could be, citing the use of aspirin due to its anti-inflammatory effects.
Read MoreAre gut bacteria the cause of metabolic syndrome?
Too much bacteria in the gut changes the way the body processes fat, and could therefore lead to the development of metabolic syndrome, according to new research. Metabolic syndrome is 3 or more of obesity, type 2 diabetes, high blood pressure, high blood sugar or increased waist circumference. Research has supported the view that plant-derived fibres are good for your health, gut bacteria can ferment them releasing energy-rich short chain fatty acids (SCFA), such as acetate and butyrate which are essential for gut health and preventing metabolic syndrome. However this research in mice suggests that when SCFAs are over-produced and reach the liver, they are converted into lipids which can then lead to the development of obesity, and subsequently metabolic syndrome.
This is likely to be a particular problem in people that lack ‘Toll-like receptor 5’ (TLR5), which is a receptor that regulates gut bacteria and keeps the microbiome stable. According to Matam Vijay-Kumar, one of the study authors, around 10% of the human population have a mutation which renders TLR5 useless, leaving individuals with weakened immune systems that are more likely to succumb to metabolic syndrome. Whilst some short chain fatty acids are beneficial in moderation, there is a worry that unchecked bacterial fermentation could lead to fat deposition in the liver and subsequent development of metabolic syndrome. Vijay-Kumar hopes that more long-term studies will be carried out to discover the full effects of fatty acids and these will eventually lead to a more personalised dietary intake for immunocompromised individuals.
Read MoreComponents of breastmilk contributing to passing on of obesity
New research has shown that complex carbohydrates found in breastmilk are associated with infant obesity. Michael Goran, the corresponding author from the Keck School of Medicine of the University of Southern California identified variations of human milk oligosaccharides (HMOs) as either protective or as risk factors for obesity. Previous studies conducted in this area have produced varying results, with most showing that breastfeeding decreases the risk of developing obesity; this study in particular looked at 71 past reports, finding breastfeeding to reduce excess weight by about 10%. However it is largely dependent on the composition of the mother’s breast milk and the specific mix of HMOs that makes the difference.
HMOs themselves can’t be digested and so accumulate in the colon and shape the gut microbiome of the baby. The study examined 25 mother and child pairs and used measures at 1 and 6 months. Although small, the study results are promising as the aim was to identify which HMOs are most important in obesity protection. Goran stated that these HMOs could then be used as supplements in those that are breastfeeding or alongside formulae. It must be stressed that breastfeeding is not being vilified in this study, only that it is helping us to understand better how a child might develop obesity, as breastfeeding has many benefits too.
Read More‘Everything in Moderation’ could be poor nutrition advice
A diverse diet may be a poorer one, and also bad for your metabolic health. Using data from 6,814 participants, scientists from the University of Texas Health Science Centre measured diet diversity and change in waist circumference over 10 years. Diet diversity is defined as less similarity amongst the foods that people eat; it was measured by the ‘total count’ (of varying foods eaten in a week), ‘evenness’ (the equality of calories spread over the foods eaten), and ‘dissimilarity’ (the characteristics of some foods that might contribute to metabolic health, for example trans-fat content or fibre).
The researchers managed to dissect the nerve fibres from mice that innervated adipocytes and assess the functional relevance of these neurones. They observed obvious fat breakdown and fat mass reduction on activation of the sympathetic neurones. This study has not only clarified how leptin has its lipolytic effect but suggests new therapeutic strategies for overcoming the central leptin resistance seen in obesity.
Read MoreHas sugar been proven to be toxic?
Reducing consumption of sugar in children, without reducing calories or losing weight, can reverse the symptoms of metabolic syndrome. It is widely known that sugar has a detrimental effect on weight, however this study from California suggests that it is metabolically harmful, simply due to the fact that it is sugar. Dr Robert Lustig, the study’s lead author, claimed that his work was the ‘strongest evidence to date that the negative effects of sugar are not because of calories or obesity’, but that it contributes to metabolic syndrome differently. The study was carried out on 43 children between the ages of 9 and 18 who were all obese, with at least one other metabolic disorder.
After evaluating total count and evenness the researchers found that there was no association with waist circumference, however, those participants with the greatest dissimilarity experienced increased weight gain. Diet quality was also measured using the Dietary Approaches to Stop Hypertension (DASH) score and the Alternative Healthy Eating Index (AHEI) score. It was found that participants that had a greater dissimilarity also had a poorer quality. This suggests that in modern diets, eating ‘everything in moderation’ could be more detrimental than eating a smaller number of healthy foods. This shows that there should be increased focus on the consumption of more healthy foods in order to create a varied diet.
Read MoreCan weight loss surgery be a cure for diabetes?
Gastric bypass surgery can lead to remission of type 2 diabetes. A recent study published in the American Journal of Physiology — Regulatory, Integrative and Comparative Physiology, aimed to find out why Roux-en-Y bypass surgery improves insulin sensitivity. Insulin transfers sugar from the blood into storage sites around the body, such as skeletal muscle and fat tissue. Poor insulin sensitivity means that that this process is slowed down, leading to a high blood sugar level, this is commonly known as type 2 diabetes and is prevalent in obese people.
The study looked at abdominal fat and thigh muscle samples taken before and after gastric bypass surgery. Significant improvement was seen in insulin sensitivity by 12 months after surgery, with the greatest improvement being noticed in fat tissue, suggesting that it plays a more prominent role in insulin sensitivity than previously thought. Overall, the study suggests interesting interactions between insulin and fat tissue, whilst showing that Roux-en-Y gastric bypass could contribute more in treating insulin sensitivity.
Read MoreBariatric surgery alters our brains
A finnish study has shown that bariatric surgery along with weight loss normalises the brains opioid neurotransmission, which is involved in generating a feeling of pleasure. The research highlights how obesity has an effect at the molecular level within the brain and how much weight loss can affect this. The findings suggest that a lack of opioid receptors (which cause a feeling of pleasure), in the brains of obese individuals, means that they must eat more in order to feel pleasure.
Furthermore, as the levels of receptors normalised after weight loss, it is understood that lower levels in obese people is a consequence of obesity, rather than a cause. This finding helps us understand the molecular involvement of obesity on a much different level than previously thought, and may provide a new option for behavioural and pharmacological treatment.
Read MoreHow much sugar is too much sugar?
A new study published in the journal Obesity has shown that proposed changes in the ‘Nutrition Facts’ label on food will help people understand how much sugar they are consuming. The Canadian study aimed to test the efficacy of formats for labelling on food, showing the total and added sugar. The researchers conducted studies on 2,000 16-24 year olds and found that adding a percentage daily value for added sugar helped them identify foods with ‘too much’ sugar in.
At first these young people found it difficult to correctly identify foods high in sugar, but with added labels and percentage values they understood more and felt that they would be less inclined to consume those foods high in sugar. The study highlights the fact that whilst it is important to research the different types of treatment for obesity, we must not forget that prevention is better than a cure and that obesity can be stopped by even the simplest of measures.
Read MoreMothers find it difficult to admit that their children are obese
Admitting that they themselves are obese is easier for a mother than admitting their child is. This comes after a study conducted in Ireland found that mothers were more honest and accurate about their own height and weight, but only 17% of mothers of obese children could admit that their child was overweight. This means that they are less likely to seek help and intervene due to their child’s weight, increasing the chances of the child gaining more weight, and eventually tracking this into adulthood.
The effect is more apparent in the cases of overweight daughters, where mothers are far less likely to admit that their daughters were obese than their sons. Identifying the problem is the first step to solving it, and by not recognising their children’s problems some mothers may be subconsciously putting their children at increased health risks. The researchers suggested that the problem may arise due to the fact that mothers are not objectively measuring their children, but could be comparing them to their peers. Furthermore, if a mother does identify her child as overweight, she may feel that she needs to intervene and upset the child, and therefore avoids this. In summary, the study called for more open and honest discussions between health professionals, parents and children in order to maintain healthy weight in the young.
Read MoreObesity rates to soar if no action is taken
New figures suggest that 2.7 billion adults will be obese by 2025. In a press release the World Obesity Federation has estimated that the global prevalence of obesity will be as high as this if current trend continue. The figures were released on the first World Obesity Day on the 11/10/2015. In the release it explains that in 2012 governments around the world committed to bringing levels of obesity back down to those that existed in 2010, by 2025. This was part of an idea developed by the WHO called the Global Action Plan for the Prevention and Control of Noncommunicable Diseases. The report suggests that the governments in question have not been doing enough to control the rise in obesity rates.
The president for the World Obesity Federation, Professor Walmir Coutinho, urged these governments to act immediately in order to halt the rise in the obesity epidemic using measures such as market controls, taxes and subsidies, whilst also setting standards for catering services and investment in healthy schools. Whilst the current prevalence of obesity is 13% worldwide, with this estimated increase it will become 17% by 2025, evidently more action needs to be taken to stop this.
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