Obesity Care

Dietary Fat, but Not Protein or Carbohydrate, Regulates Energy Intake and Causes Adiposity in Mice

The debate on the importance of different macronutrient configurations on body composition has driven many debates and fad-diets. In this new study in mice, published in Cell Metabolism, high dietary fat has been found to be the one diet that was associated with higher energy intake and adiposity.

The study, which involved the controlled feeding of mice 29 different diets varying from 8.3% to 80% fat, 10% to 80% carbohydrate, 5% to 30% protein, and 5% to 30% sucrose, also found an association with increased gene expression of different receptors in the brain. There was increased expression of 5-HT receptors, as well as the dopamine and opioid signalling pathways in the hypothalamus.

It has been documented that mice regulate their energy needs, and thus food consumption, based on caloric, as opposed to protein requirement. However, this study seems to suggest that this system can be compromised by hedonic factors linked to fat, but not carbohydrates. Although this is a long way from proving anything in humans, the shared similarities in energy regulation centres between the two species means that it is possible to speculate that humans share this hedonic factor override of energy regulation systems, which may provide an explanation to unhealthy eating behaviours such as binge eating.

The cost-effectiveness of OPTIFAST for the treatment of obesity

This study, published in the Journal of Medical Economics, assesses the potential cost-savings of using the OPTIFAST program in a population of US subjects, in comparison to “No intervention” and pharmacotherapy (liraglutide and naltrexone-bupropion).

OPTIFAST is a scientifically proven and medically supervised low-calorie diet program, for individuals with overweight and obesity. It has been shown to achieve acute and sustained weight loss, and reduction of clinical complications of obesity in studies since the 1980s. It involves providing obese patients with a 12 week diet of total meal replacement, with 2 subsequent phases of transition to a food based diet for 12 weeks each, and then another phase of 24 weeks. The total costs of the program is USD 4,500, which consists of USD 1,500 for the meals, and USD 3,000 for the weight management programme.

In the US at the moment, the threshold of willingness to pay for a new medicinal product per QALY is ~USD 50,000. A QALY is equal to one year of life lived in perfect health, and is calculated on numerous factors that assess quality-of-life systematically. This study has found that the cost of a QALY using OPTIFAST is USD 6,475, which is far below the threshold and represents great value for money. One of the reasons for this is the significantly lower incidence of complications, as compared with “no-intervention” and liraglutide or naltrexone-bupropion, in patients with class I or II obesity. This benefit is even more meaningful in class III obese patients with T2DM, and further increases with more time on the programme.

OPTIFAST has been demonstrated to lower healthcare costs, even when compared with bariatric surgery. Furthermore is has additional clinical and socio-economic advantages, due to few and mild adverse events when compared to other treatment regimes.

Lifetime costs of obesity in childhood are growing

In this systematic review published in Paediatric Obesity, the authors sought to establish the costs of childhood and adolescent obesity in terms of direct healthcare costs as well as indirect productivity costs. Direct costs include drug costs, hospital in-patient costs, hospital outpatient costs and primary care costs. Indirect costs are divided into costs to society because of workdays lost and income penalty. Lost workdays accumulates the days lost to morbidity, early-retirement and mortality, whereas income penalty tries to assess how being overweight or obese may result in lower salary level.

Using 13 published research articles, they were able to work out that the average total cost was €149,206 for boys and €148,196 for girls. When this number was further broken down, it was found that lifetime cost was proportional to BMI, with lifetime costs increasing in proportion with excess weight during childhood or adolescence. It also found that productivity costs are significantly greater than healthcare costs, with girls being more likely to suffer increased healthcare costs and income penalties, and boys more likely to have increased work days lost.

An erroneous picture of the true cost obesity is created by studies which only focus on the direct costs of obesity. This study admits that the average figure, in the region of €150,000, is probably an underestimate due to the numerous costs which cannot be captured. This indicates a need for further research into the total excess lifetime costs of childhood and adolescent overweight and obesity, as only when this is properly evaluated can public health officials begin to allocate adequate resources.

Analysis of Cardiometabolic Outcomes Associated with Self-Perceived Obesity in Korean Adults

A growing body of evidence is suggesting that self-perception of overweight/obese status is associated with poor cardiometabolic outcomes, above and beyond actual body weight. This study, conducted in Korea, used survey data from 21,629 people to determine whether there was a correlation between self-perceived obesity and metabolic syndrome (MetS) and cardiometabolic risk factors (CMRs).

In South Korea there has been a worsening of metabolic health indicators over the past decade, with obesity increasing as well as the prevalence of MetS and CMRs. This study found that individuals who identified their weight status as being slightly/very obese (vs. normal weight), were 18-54% more likely to meet MetS criteria. This was greater in men compared with women.

The findings were also in line with previous evidence showing a protective association of perception of normal weight with weight change and depressive symptoms among adolescents and young adults with overweight and obesity.

Recent studies have focussed on emotional responses related with perception of size when trying to understand the link between weight perception, cardiometabolic and emotional responses. They suggest that due to negative societal values towards obesity, self-evaluation of being obese could be associated with weight bias internalization, low self esteem and body dissatisfaction. Weight stigma is prevalent across diverse social groups and weight discrimination can induce sustained psychological distress and maladaptive coping behaviours, which can lead to biological alterations, such as prolonged activation of the hypothalamic-pituitary-adrenal axis and cortisol secretion.

Although this data can not infer any reverse causality between weight perception and metabolic outcomes, it does add to the growing body of evidence that these two are related and it is also the first to demonstrate this in a solely Asian study population. Their findings raise concerns regarding awareness orientated weight management approaches, such as BMI cards, as these may have the unintended consequence of “accurate” perception among individuals with obesity, leading to side-effects on the psychological and metabolic health of the patient. The implication of these findings on clinical practice, could be that clinicians should now take information on patients weight perception, when assessing risk of cardiometabolic dysregulation. Furthermore at policy level, intervention strategies could place the emphasis on lifestyle adjustments, such as healthy eating and increased physical activity, rather than just on the weight aspect.

Effects of Characterising ‘Obesity as a Disease’ on Weight Bias

This study sought to work out the implications of categorising obesity as a disease on weight bias. A sample of 309 participants were recruited and measures of demographics, ideology, general attitudes and previous contact with people living with obesity were taken. Participants then read one of three articles as part of an experimental manipulation, one framing obesity as a disease, one framing it not as a disease and a control article on an unrelated topic. After reading, the participants were reassessed for measures including disgust, empathy, blame and weight bias.

The ‘obesity is a disease’ manipulation had a direct positive effect on the emotional response of the participants towards individuals with obesity, because of a reduction in blameworthiness and controllability. However, this was complicated due to a heightening of essentialism; by perceiving obesity as an inherent component of the individual,  the individual becomes bad because obesity is bad. This means that framing obesity as a disease which is out of the control of the individual, is not without its consequences to weight stigma.

Another interesting finding was that those participants that had a strong ‘just-world’ beliefs, defined as those that think that people get what they deserve, and thus readily attribute blame to others misfortune in order maintain that belief. This subgroup were most susceptible to a change in emotion when given the article on ‘obesity is a disease’. This suggests that prejudice reduction strategies may need to be more specific and targeted, depending on the group that one is seeking to influence.

This study highlights the nuanced approach that must be taken when trying to implement a stigma reduction programme. Characterising obesity as a disease does not straightforwardly reduce stigma. It also highlights the importance of understanding the target audience when conducting a stigma reduction programme, as a huge number of personal variables, such as political and philosophical views, affects how they react to the information, and these must be taken into account  in order to make the programme effective.

Weight-Related Stigma is Associated with Bodily Pain Among Females with Overweight or Obesity

Pain is a common comorbidity among individuals living with overweight or obesity, however the mechanism linking the two is not clear. This studyevaluated the relationship between perceived weight-stigma and self reported bodily pain in a sample of obese/overweight adult women through questionnaires designed to measure both.

They found that perceived stigma and internalised stigma were associated with physical pain. Weight-related stigma among women with overweight or obesity appears to be associated with greater experience of physical pain. There is evidence that social and physical pain may be processed through similar physiological mechanisms and that weight stigma may potentiate the experience of pain through those neuroanatomical pathways.

What is known so far is that social factors, such as major life stressors (eg. trauma) and chronic exposure to socially painful situations (eg. conflict or isolation), increase vulnerability to pain by causing  heightened sensitivity to painful stimuli. Alongside this, permanent social stress is also thought to affect an individual’s resilience to pain. If they lack meaningful social ties and are in a negative emotional state then they’re less capable of sharing the burden and thus coping with pain.

Although more research needs to be done to evaluate the mechanisms behind this process, these findings suggest that clinicians should be considering stigma internalisation when treating obese patients suffering from chronic bodily pain.

Impact of Early‐Life Weight on Cognitive Abilities in Children

A developing child’s mind is highly sensitive to environmental factors and it is now well known that overweight and obesity has a significant impact on the metabolic and endocrine profile of  an individual. This new study, published in Obesity, sets sets out to try and determine if childhood obesity has any effect on cognitive ability, guided by the hypothesis that the production of adipocytokines and inflammatory molecules may adversely affect neurodevelopment.

The study included 233 children, who underwent measurements of weight and height to formulate a WHZ score, in the first two years of life. Then through ages 5 to 8 years, the children underwent a comprehensive assessment of cognitive abilities, including attention, impulsivity, working memory and reference memory.

Their findings suggest that early high WHZ, may be inversely associated with full scale IQ, perceptual reasoning index and working memory index, after adjusting for potential confounders. It also found slower reaction time and lower continuous performance test scores. The other cognitive tests conducted did not find an association with early-life WHZ.

The strength of this study is that it used prospective data which enabled them to investigate weight status in the first 2 years of life, which are critical to brain development. This allowed for better understanding of the direction of the association. Furthermore the cognitive tests were repeatedly administered by professionals, and encompassed a comprehensive array of cognitive abilities, which previous studies had not done. FInally they also accounted for covariates, such as socioeconomic status, perinatal factors and maternal IQ.

From this they are able to conclude that early-life obesity seems to affect full scale IQ, perceptual reasoning and working memory scores (boys only), as well as increasing reaction times among school aged children. More research needs to be conducted to confirm these findings, and the authors suggest also measuring school performance, ADHD diagnosis, learning disabilities or special education service use.

A Study of Weight Stigma Experienced by Mature Patients with Obesity in Disadvantaged Areas of Australia

There is a growing recognition of the impact stigma has on the health seeking behaviors and self-efficacy of obese patients.This study,set out to identify predictors of perceived weight stigma among patients attending general practices in socioeconomically disadvantaged urban areas of Australia. The predictors selected were socioeconomic factors (age, sex, language spoken at home, education level, and occupation), obesity category and healthy literacy.

To measure stigma, they used two items from the The Impact of Weight on Quality-of-Life-Lite Measurethat focussed on direct experiences of stigma, such as being ridiculed or teased. From it’s sample size of 120, this study found that one-third of the sample had experienced direct forms of weight discrimination in the week prior to being interviewed. The strongest predictors of stigma were higher obesity category, coming from a home where english is not the first language, being unemployed, and scoring low on the health literacy questionnaire on questions relating to ability to engage healthcare providers.

Interestingly, this study found no significant correlation between age, sex or race, which have been well documented as predictors of stigma in the USA. This study highlights the importance of tackling stigma in the healthcare setting, as well as the need for equipping these patients with coping mechanisms. In patients that are already at a disadvantage with regards to receiving healthcare, it is imperative that programmes are implemented to tackle stigma, as it can compound the disadvantaged position of these individuals, and further act as a barrier to them seeking medical help.

Association between obesity with disease-free survival and overall survival in triple-negative breast cancer: A meta-analysis

In a systematic review, published in Medicine, the authors sought to investigate whether obesity conveyed a benefit to disease-free survival (DFS) and overall survival (OS) in patients with triple-negative breast cancer. Breast cancer is a complex condition with many different subtypes, which each behave in different ways. Triple negative breast cancer means that there is not enough expression of three receptors, ER, PR and HER-2. It is a rare and often aggressive form of breast cancer, characterised by short recurrence time and greater chance of metastasis via the bloodstream.

The effect of obesity on cancer survival is still contested, and it varies between each type of cancer. The rationale behind it increasing survival is that by having a greater body mass, an obese patient is better able to survive the wasting effects of cancer and its treatment. Conversely, it is argued that many endocrine, metabolic and inflammatory complications that result from a persistent obese state, predispose these patients to cancer and limits there survival ability. This review included data from 9 studies for DFS meta-analysis (4,412 patients) and 8 studies for OS meta-analysis (4,392 patients). It found a number of controversial studies, which suggested obesity conveyed a very significant survival advantage, and others, which concluded that the opposite was true. The result of their analysis is that there was no statistically significant difference between the DFS and OS rates of obese patients compared to normal weight patients in triple negative breast cancer.

Effects of Physical Activity and Sedentary Behaviour on Brain Response to High‐Calorie Food Cues in Young Adults

Physical activity is known to be an effective method of weight management, due to increased burning of calories. However, this study published in Obesity, found that beyond the calorific effect, there is also a physiological change in the brain in areas associated with reward.

For this study, 22 lean and 18 obese people were selected and their activity levels assessed. Looking at levels of moderate to vigorous physical activity (MVPA), and levels of sedentary behaviour (SB). Next, they ingested some glucose and underwent an fMRI brain scan, and while in the scanner, they were shown images of high-calorie foods, alongside inanimate objects. The researchers looked at 10 regions of the brain known to be responsive to visual food cues. What they found is that those who engaged in MVPA had lower responses to the food cues, and those who engaged in SB, had higher responses. This was true of the healthy weight individuals, and particularly true amongst the obese participants.

The potential mechanism through which physical activity suppresses responses to food cues is still unclear, however what is clear is that reducing SB and increasing MVPA can have positive effects on regions of the brain associated with food perception. Future studies on the underlying mediators of the effects of physical activity on the brain’s response to unhealthy food cues, may provide an interesting new approach to treating obesity.  

Identification of Children’s BMI Trajectories and Prediction from Weight Gain in Infancy

The causes of childhood obesity are not always clear; however, the risk that it poses to adult health outcomes, such as cardiovascular health and premature death, mean that an understanding of common patterns and predictors in infancy are essential. This paper published in Obesity, used data on birthweight and BMI from 1,364 children of ages 24 months to 13 years, to see which patterns are associated with higher risk of becoming overweight or obese.

They found that risk of membership of a high-BMI trajectory could be predicted from as early as 15 months old. Birth weight for gestational age and percent weight increase in the first 15 months are the strongest predictors for following a high-rising trajectory of weight change across childhood. Therefore, high-birth weight should trigger parents and physicians to ensure healthy nutrition. More importantly than that, rapid weight gain in the first 15 months was found to be strongly correlated to high-BMI in later life, meaning that close monitoring of weight-gain in early life, along with intervention, could be a new way of preventing childhood obesity.

Metabolically Healthy Obesity, Transition to Metabolic Syndrome, and Cardiovascular Risk

This study, published in the Journal of the American College of Cardiology, used data from 6,089 participants of the MESA study to see how having a healthy metabolic profile despite obesity, affects your risk of cardiovascular disease.

The debate over the risk of cardiovascular disease (CVD) associated with the three groups, metabolically healthy normal (MHN), metabolically healthy obese (MHO) and metabolically unhealthy obese (MUO), stems from the apparent contradiction that an individual can be obese (BMI>30 Kg/m2) and yet be free of metabolic syndrome (MetS). This study found that for the vast majority of people, MHO was a transition state towards MUO, and that there was a dosing effect associated with obesity. With the risk of developing MetS being relative to cumulative obesity exposure. They found that almost one-half of those with MHO at baseline, developed MetS during follow-up. Higher MetS duration was also significantly associated with CVD, supporting the theory that risk from obesity is cumulative.

Very few individuals can stay metabolically healthy when continuously exposed to obesity, and the transition to MetS represents a massive increase in risk of CVD. Clinicians should see MHO as an opportunity for early intervention, to prevent later disease, rather than waiting for an unhealthy metabolic profile to develop, by which point, risk has already massively gone up.