Before you respond “of course” – you may wish to take a look at the systematic review by Laura Cobb and colleagues from Johns Hopkins University, published in OBESITY.
The authors looked at 71 Canadian and US studies that examined the relationship between obesity and retail food environments and concluded that,
“Despite the large number of studies, we found limited evidence for associations between local food environments and obesity. “
To be fair, the researchers also concluded that much of the research in this area lacks high-quality studies, that would lead to a more robust understanding of this issue.
In fact, the authors had to slice and dice the data to tease out “positive” findings that included a possible relationship between fast food outlets and obesity in low-income children or an inverse trend for obesity with the availability of supermarkets (a supposed surrogate measure for availability of fresh produce).
Of course, not finding a robust relationship between the food environment and obesity should not be all that surprising, given the many factors that can potentially play a role in obesity rates.
(Readers may recall that there used to be similar enthusiasm between the role of the built environment (e.g. walkability) for rising obesity rates, till the research on this issue turned out to be rather inconclusive. )
None of this should be interpreted to mean that the food or built environments have nothing to do with obesity – however, we must remember that these type of studies virtually never prove causality and that the factors that determine food and built environments are in fact almost as complicated as the factors that determine individual body weights, so finding a robust relationship between the two would be rather surprising.
Allow me to predict that with the increasing trend of fast food outlets offering healthier (or rather less-unhealthy) choices and supermarkets offering ample amounts of “fast food” and a vast array of unhealthy packaged foods, any relationship between retail food environments and obesity (even if it does exist), will be even harder to prove that ever before (outliers are no better than anecdotal evidence and should generally be ignored).
Changing food environments to provide better access to affordable healthier foods should be a “no-brainer” for policy makers, irrespective of whether or not the current environment has anything to do with obesity or not (the same could be said for walkability of neighbourhoods and the prevention of urban sprawl).
This week, the New England Journal of Medicine publishes the results of the SCALE Trial, a 56-week randomised controlled trial of liraglutide 3.0 mg vs. placebo (both groups got advice on diet and exercise), on weight loss and other metabolic variables.
The study, that enrolled about 3,700 subjects (70% of who completed the trial), showed greater clinically relevant weight loss in participants treated with liraglutide than with placebo.
Overall, at 56 weeks,
– 2 in 3 individuals on liraglutide achieved a 5% weight loss (compared to 1 in 4 on placebo).
– 1 in 3 individuals on liraglutide achieved a 10% weight loss (compared to 1 in 10 on placebo).
– 1 in 6 individuals on liraglutide achieved a 15% weight loss (compared to fewer than 1 in 20 on placebo).
The adverse effect profile was as expected from a GLP-1 analogue (mainly gastrointestinal and gall bladder related issues).
While liraglutide 3.o mg has now been approved as an anti-obesity agent in the US, Canada and Europe, its key downsides will likely be cost and the fact that it consists of a once-daily injection.
Obviously, as with any obesity treatment, discontinuation will likely result in weight regain (which is not unexpected, given that obesity, once established, becomes a chronic disease).
While in the US, where there are now 4 novel prescription medications for obesity, liraglutide 3.o mg will be the only novel anti-obesity drug available in Canada – a rather sorry state of affairs for those who need medical treatment for this condition.
Where exactly liraglutide will establish itself in the treatment of obesity in clinical practice remains to be seen (time will tell) – but for some patients at least (especially the high-responders), it will hopefully offer a useful adjunct to behavioural treatments.
Disclaimer: I have received honoraria for consulting and speaking from Novo Nordisk, the makers of liraglutide
Today’s guest post comes from Catherine B. Chan and Rhonda C. Bell, Professors in Human Nutrition at the University of Alberta. It describes their Pure Prairie Eating Plan (PPEP) and how they went about developing this rather unique venture into eating local.
Healthy eating is a key factor in preventing and treating chronic diseases such as heart disease, stroke, cancer and diabetes. According to the World Health Organization, good nutrition is one of 4 key factors that could help postpone or avoid 90% of type 2 diabetes and 80% of coronary heart disease.
The Mediterranean Diet has gained popularity as a healthy diet, but evidence gathered through research on Canadian prairiegrown products (canola, flax, barley, pulses, dairy and meats) demonstrates that many local foods have similar nutritional qualities and would be more acceptable and accessible to people who live in Alberta, Saskatchewan and Manitoba.
Our recent project was conceived to develop, test and demonstrate the potential health benefits of a dietary pattern based on foods that are commonly grown and consumed in a “made in Canada” menu plan.
How the Pure Prairie Eating Plan (PPEP) was developed
The original purpose of the menu plan was to help people with type 2 diabetes adhere to the nutrition recommendations of the Canadian Diabetes Association (CDA) by focusing on healthy food choices with a local flavour. The menu plan concept integrates knowledge gained through research related to consumer behavior, behavior change, and nutritional quality of dairy, meats,
canola, pulses and grains.
During its development, it was recognized that a diet healthy for people with diabetes is a diet healthy for everyone. This notion was reinforced in a Consensus Conference with people living with type 2 diabetes, who felt strongly that their diet should not be different from others.
This approach provided knowledge that formed the basis of a 4-week menu plan focused on foods that are grown and readily available in the Canadian prairies. The plan consists of 28 days of diabetes-friendly menus including 3 meals and 3 snacks each day, approximately 100 recipes, tips for healthy eating, pantry and grocery lists and other helpful information.
If followed consistently, the menus meet the recommendations of Eating Well with Canada’s Food Guide on a daily basis, and over 1 week averages approximately 2000 kcal/day with macronutrient distribution consistent with health recommendations.
The menus also provide total fibre between 25 and 50 g/day. Many of the recipes have been obtained from our provincial agricultural commodity groups (see http://pureprairie.ca/oursponsors/).
The recipe ingredients feature many homegrown foods from each food group. They are quick and easy to make…and tasty!
Our Research Findings
Funding was secured through the Alberta Diabetes Institute to pilot test the menu plan concept in a 12-week intervention that measured both quantitative (disease biomarkers) and qualitative (acceptability, accessibility and acceptability) responses to the menu plan of 15 people with type 2 diabetes.
The results, published in the Canadian Journal of Diabetes, showed that most participants liked the menu plan and their A1c decreased by an average of 1%.
However, many were not used to cooking from scratch and cited time as a barrier to using the menu plan more. The benefits of the menu plan included more structure in participants’ diets, increased frequency of snacking, increased awareness of food choices, purchasing healthier foods and better portion control.
Participants were aware of better blood sugar control. Participants were pleased with the variety of food choices and liked the taste of the recipes. They also liked the flexibility of the menu plan.
In the second phase, which included 73 participants, we included a 5-week curriculum delivered in a smallgroup setting with a facilitator and included assessment of hemoglobin A1c as a measure of blood sugar control as well as cardiovascular risk factors. Nutrient intake was assessed using a computerbased 24-hour recall system called WebSpan.
In this study, 86% of those enrolled completed all aspects of the programme, including the 3-month followup. On average, there were decreases in A1c (0.7%), body mass index (0.6 kg/m2) and waist circumference (2 cm). (Note that a decrease in A1c of 0.5% is considered to be a clinically relevant improvement in blood sugar control.)
Although the weight loss was relatively small, it correlated with the reduction in A1c more strongly than any other factor examined.
Analysis of nutrient intakes showed decreases in total energy intake (127 kcal/day), total fat (7 g), total sugar (25 g) and sodium (469 mg).
The Pure Prairie Eating Plan (PPEP)
With promising outcomes regarding the nutritional adequacy and acceptability of the menu plan, and with encouragement from Alberta agricultural commodity groups and others, we packaged and rebranded the menu plan as the Pure Prairie Eating Plan (PPEP): Fresh Food, Practical Menus and a Healthy Lifestyle.
PPEP is available for purchase in selected bookstores throughout the prairies and proceeds from its sale will be used to further research into improving the lifestyle behaviours of Canadians with or at risk of chronic diseases.
For a listing of bookstores currently stocking PPEP, or to buy online, click here
Healthcare providers wishing to purchase 6 copies or more can contact firstname.lastname@example.org for a discount.
We would like to acknowledge the financial support of our sponsors.
Dr. Catherine Chan is Professor of Human Nutrition and Physiology at the University of Alberta. Her research (Physical Activity and Nutrition for Diabetes in Alberta, PANDA) focuses on the development, implementation and evaluation of healthy behavior interventions as well as on identification and testing of healthy food ingredients. She is also the Scientific Director for the
Diabetes, Obesity and Nutrition Strategic Clinical Network of Alberta Health Services.
Dr. Rhonda Bell is Professor of Human Nutrition and leader of the ENRICH project (Promoting Appropriate Maternal Body Weight in Pregnancy and Postpartum through Health Eating) at the University of Alberta. The ENRICH project aims to develop and promote practical strategies for women to maintain healthier weights during and following pregnancy.
As regular readers may know, the Canadian Obesity Network is currently promoting the creation of local chapters across Canada. This is part of the Network’s strategy to continue growing and engaging researchers, health professionals, and others with an interest in obesity prevention and management to network and break down silos.
Following the very successful launch of local Obesity Network chapters in Calgary and Hamilton, last night saw the inaugural meeting of the Toronto Chapter (CON-YYZ), which got together to appoint their new executive and to exchange ideas on local activities that this chapter can pursue in the future.
I had the opportunity of joining in for part of this meeting via Skype and was delighted to see the diversity of attendees and their enthusiasm – certainly a promise of great things to come.
For anyone interested in learning more about how to start your own local CON chapter, more information is available here.
I look forward to seeing a number of new Obesity Network chapters created across Canada, as we continue to seek better ways to fight weight-bias, discrimination and find better ways to prevent and manage obesity.
Today’s guest post comes from Kristy Wittmeier, PhD (and CON Bootcamper), a physiotherapist at the Winnipeg Health Sciences Centre and Director of Knowledge Translation at the Manitoba Centre for Healthcare Innovation. She has a special interest in physical activity as a tool to prevent and manage obesity-related conditions in youth. Her current positions and affiliation with the Children’s Hospital Research Institute of Manitoba allow her to combine research and practice to improve patient outcomes. Twitter: @KristyWittmeier
If you were trying to build a coordinated provincial strategy to promote healthy weight in children and youth, where would you start? This has been a question on the minds of a team of healthcare providers and researchers in Manitoba for some time now.
Manitoba has the highest rate of type 2 diabetes in children in Canada, a condition that is in part related to obesity. In Manitoba, youth are diagnosed with type 2 diabetes at a rate 20 times higher than in any other province.
There are well-established, multidisciplinary clinical programs in our province that work with youth living with type 2 diabetes. For example, the Diabetes Education Resource for Children and Adolescents, which has existed since 1985, runs two weekly clinics and an outreach program for youth affected by type 2 diabetes.
Recently, the diabetes care team joined forces with pediatric kidney specialists in the province to provide a combined clinic for youth affected by both type 2 diabetes and kidney complications.
Manitoba is also home to the Maestro Project, which helps teens living with type 2 diabetes navigate what could otherwise be a difficult transition from pediatric to adult health care services and teams.
Similarly, research teams that include community advisors and families are tackling important questions related to the origins of type 2 diabetes and exploring innovative interventions to improve the health and quality of life for kids with this diagnosis.
Members of the DREAM (Diabetes Research Envisioned and Accomplished in Manitoba) Theme at the Children’s Hospital Research Institute of Manitoba are studying important biological, social and psychological factors linked with early kidney disease in youth with type 2 diabetes in a study called iCARE (Improving renal Complications in Adolescents with type 2 diabetes through REsearch).
While we have made significant progress in the area of type 2 diabetes care and research, we have made less progress in the areas of prevention and treatment of obesity in children and youth. We are one of the few provinces in Canada without a specialized clinical team dedicated to pediatric obesity. We lack a comprehensive provincial strategy that can link health care providers to each other, or to existing community programs that might help families. Gaps in services can leave families without access to care that could help their children. This is the issue that we have decided to tackle in a study that was recently funded by the Children’s Hospital Research Institute of Manitoba.
Our study is called “Mapping the state of pediatric weight management programs in Manitoba.” We will start with a survey within Manitoba, to identify existing programs that are available to families affected by obesity in our province. We want to know what is currently available. Where can health care providers refer families? And importantly, what resources are missing in our province to be able to provide an evidence-based approach to pediatric weight management?
While the title suggests we are solely focused on Manitoba, we are in fact looking to shape our provinces’ approach by learning from others across Canada and the United States.
To do this, the second part of the study will involve updating a 2010 study that mapped Canadian pediatric weight management programs to understand what has changed on the national landscape. What new programs exist and where? What programs are no longer offered and why?
Then we will move on to more in-depth conversations with members of the eight clinics involved in the Canadian Pediatric Weight Management Registry (CANPWR), and an additional eight clinics in the United States to better understand how their approaches evolved, barriers and successes that they have experienced and other key learnings that they can share to help inform a Manitoba approach.
Once we have brought the information from these activities together, we will hold a meeting for families, community members, clinicians, researchers, healthy living organizations and policy makers in the province. We will look at the data together and prioritize the next important steps on this journey.
We all need to work together to build healthier families, healthier communities and healthier populations. This novel approach that integrates the experiences and priorities of others will ensure that when we launch a new direction for pediatric obesity management in Manitoba, it will be relevant and targeted to everyone’s needs.
Last week I posted on the importance of non-acoholic fatty liver disease as one of the most common yet insidious consequences of obesity.
Now, a paper by Bower and colleagues from Imperial College London, published in Obesity Surgery, provides a systematic review of the impact of bariatric surgery on liver biochemistry and histology.
The review clearly shows that bariatric surgery is associated with a significant reduction in the steatosis, fibrosis, hepatocyte ballooning and lobular inflammation. Surgery is also associated with a reduction in liver enzyme levels, with statistically significant reductions in ALT, AST, ALP and gamma-GT.
However, there is considerable variability in these outcomes and between different types of interventions – clearly suggesting that more research on this issue is needed.
Nevertheless, at this time it appears that bariatric surgery may well be the most effective treatment for fatty liver disease.
As regular readers are well aware, obesity is a chronic disease which simply means that any treatment you decide to pursue needs to be one you can stick with in the long-term (this applies as much to your diet as it does to taking an anti-obesity drug or, for that matter having surgery – when the treatment stops the weight comes back!).
That said, it would be easy to assume that if you chose (or otherwise have a say) in the kind of diet you think will help you manage your weight, you’d a) lose more weight and b) be more likely to keep it off.
As a randomised controlled study by Annals of Internal Medicine, neither of these assumptions may be true.Duke University Medical Center, Durham, North Carolina, published in the
The researchers randomised 207 participants to two groups – a choice group in which participants had the choice of going either on a low-carbohydrate (less than 20 g/day) or low-fat diet (less than 30% energy from fat).
The non-choice group was not given this choice but were randomly assigned to either of these diets. Both groups were provided with group and telephone counseling for 48 weeks.
Of the 105 choice participants, 58% chose low-carb and 44% chose low-fat – 83% completed the study – and lost on average 5.7Kg.
Of the 102 non-choice participants, 52 % were assigned to low-carb and 48% to low-fat – 86% completed the study – and lost on average 6.7 Kg.
Of note, the actual reported intake of carb in the low-carb groups ranged between 45-80 g of carbs per day (down from about 200 g/day) while fat intake in this group increased from about 40 to 55% of total energy); In the low-fat group, actual fat intake, fell from about 40% at baseline to about 35% on the diet.
There were no difference in dietary adherence, physical activity or quality of life.
This study illustrates that whether or not you get to chose your preferred diet or not doesn’t matter – what does is that you stick with it.
Or as the authors put it,
“The double-randomized preference design of our study allowed us to determine that preference did not meaningfully affect weight loss. Moreover, the range of estimated weight differences between groups in the 95% CIs does not contain a clinically meaningful difference in favor of the choice group.”
Both findings may not be exactly what one may have predicted – which is exactly why we need these types of studies.
With all the concern about the impact of obesity on metabolic and cardiovascular health, it is often forgotten that after smoking, obesity is the single most important risk factor for many common cancers, including of course breast cancer.
The importance of this relationship is again documented by Marian Neuhouser and colleagues in a paper published in JAMA Oncology.
The study examines the associations of overweight and obesity with risk of postmenopausal invasive breast cancer after extended follow-up (about 13 years) in the Women’s Health Initiative (WHI) clinical trials, involving over 67,000 postmenopausal women ages 50 to 79 years at 40 US clinical centers..
Overall, 3388 invasive breast cancers were observed over the follow-up period with women who were overweight or obese having increased risk that was related to their degree of excess weight.
Compared to normal weight women, individuals with Class II and III obesity had a 60% greater risk for invasive breast cancer with an almost 2-fold greater risk for estrogen receptor–positive and progesterone receptor–positive breast cancers.
Class II and III obesity was also associated with a 2-fold greater risk for larger tumor size, positive lymph nodes and deaths.
Furthermore, risk was increased in women with a baseline BMI of less than 25.0 who gained more than 5% of body weight over the follow-up period.
Given this importance of obesity for breast cancer, one can only wonder just how much of the Cancer research funding raised by the Pink Ribbon campaign and other Cancer charities, finds its way into research on obesity treatment and prevention – can’t say I know of any cancer funding that has knocked on the doors of my fellow obesity researchers.