The past two days, I’ve been at a young investigator’s meeting convened by the Canadian Institutes of Health Research Institute for Nutrition, Metabolism and Diabetes, in Kelowna, BC.
This annual event brings together promising and emerging young investigators working in the fields of metabolic, renal and digestive disease from across Canada.
The talks by experienced faculty are given on topics ranging from grant writing, finding a good mentor and building partnerships (my topic), to the importance of not forgetting about work-life balance.
There is no doubt that every year, the research environment for funding becomes yet more competitive. Thus, it is always refreshing to see the enthusiasm, passion and enthusiasm with which young researchers approach the many research questions that desperately need answers.
Finding better ways to prevent and treat obesity are certainly among the top issues on the list, and it was therefore not surprising to see several of the research projects presented by the young attendees focusing on various aspects of obesity.
I found attending this event particularly rewarding as this was a reunion with several past “bootcampers” (attendees of the Canadian Obesity Network’s annual Obesity Research Summer School), who, I am happy to say, have progressed nicely into junior faculty and new investigator positions.
Congratulations to the organisers and all who had the privilege of attending.
Now a study by Crump and colleagues published in JAMA Intern Medicine suggests that some of this risk may be mitigated by increased physical fitness.
The cohort study involving over 1.5 million Swedish young men in Sweden, who underwent standardized aerobic capacity, muscular strength, and BMI measurements obtained at a military conscription examination and were followed for up to 40 years.
Almost 100,000 men went on to develop hypertension, whereby both high BMI and low aerobic capacity (but not muscular strength) were associated with increased risk of hypertension, independent of family history or socioeconomic factors.
A combination of high BMI (overweight or obese vs normal) and low aerobic capacity (lowest vs highest tertile) was associated with the highest risk of hypertension.
The association with aerobic fitness was apparent at every level of BMI.
Form this study the authors conclude that high BMI and low aerobic capacity in late adolescence are associated with higher risk of hypertension in adulthood.
Although one must also be cautious in assuming causality with regard to associations found in such studies, the observations are certainly compatible with the notion that increased cardiorespiratory fitness may well mitigate some of the impact of increased BMI on hypertension risk.
This is even more true for children with physical disabilities, who face even greater challenges when it comes to preventing or managing excessive weight gain. Unfortunately, not much is known about the extent of this problem or possible solutions.
Now a group of Canadian experts in paediatrics and rehabilitation have put out a Call to Action, published in Childhood Obesity, for a research agenda that focuses on this important sub-group of kids.
The call is the result of a Canadian multistakeholder workshop on the topic of obesity and health in children with physical disabilities that was held in October 2014.
The participants in the workshop included researchers, clinicians, parents, former clients with disabilities, community partners, and decision makers.
Given the paucity of research in this area, it is not surprising that the participants identified over 70 specific knowledge gaps that fell into 6 themes: (1) early, sustained engagement of families; (2) rethinking determinants of obesity and health; (3) maximizing impact of research; (4) inclusive integrated interventions; (5) evidence-informed measurement and outcomes; and (6) reducing weight biases.
Within each theme area, participants identified potential challenges and opportunities related to (1) clinical practice and education; (2) research (subareas: funding and methodological issues; client and family engagement issues; and targeted areas to conduct research); and (3) policy-related issues and topic positioning.
Recommendations emerging from the workshop’s multistakeholder consensus activities included:
Children’s and families’ needs must be integrated into prevention and treatment programs, taking into account the additional caring commitments and environmental challenges often experienced by families of children with physical disabilities. Guidelines need to be developed regarding how best to engage children/families meaningfully in designing both clinical interventions and health promotion research initiatives.
Research in obesity and health in children with physical disabilities should be guided by a conceptual model, determining both common and unique determinants of health and obesity compared with their typically developing peers. A conceptual model enables existing knowledge about obesity prevention and management from other populations to be integrated into approaches for children with physical disabilities where appropriate, as well as the identification of areas where disability-specific knowledge is still needed. It is critical that any such model incorporates social and environmental factors that can affect both weight and health, rather than locating responsibility within the individual by default.45 The alignment of our model with the ICF ensures that our approach remains truly biopsychosocial.
Valid, reliable, clinically appropriate, and acceptable outcome measures are urgently needed in order to monitor children’s weight and health, and identify overweight and obesity, where conventional outcomes (e.g., BMI) alone have been shown as suboptimal.
As the authors note,
“Canadian researchers are now well positioned to work toward a greater understanding of weight-related topics in children with physical disabilities, with the aim of developing evidence-based and salient obesity prevention and treatment approaches.”
Hopefully, they will now find the funding required to do the work.
Interestingly, despite the popularity of this device, studies in scientific journals using Fitbit as an intervention to increase physical activity are rather sparse (most studies focus on validity of measurement).
Thus, I was interested in a study by Lisa Cadmus-Bertram and colleagues from the University of Wisconsin published in JMIR mHealth.
The rather small study involved 25 overweight or obese, postmenopausal women enrolled in the intervention arm of a randomized controlled physical activity intervention trial.
Over 16 weeks, each participant was advised to use the Fitbit physical activity tracker and website.
Evidently, the participants were happy wearing the device as the median participant logged 10 hours or more/day of Fitbit wear on 95% of the 112 intervention days, with no significant decline in wear over the study period.
Overall, participants averaged 7,540 (goal 10,000) steps/day and 82 minutes/week (goal 150) of accumulated “fairly active” and “very active” minutes during the intervention.
After peaking at 3 weeks, there was a small declines of 8% for steps and 14% for MVPA by 16 weeks.
So the devices were used and the participants did achieve and maintain a moderate level of daily physical activity.
The question remains, however, as to how representative these data actually are. After all these were a rather small number of volunteers in a research study – perhaps not your everyday user.
Nevertheless, the benefits of self-monitoring for self-management of chronic diseases (including obesity) are undisputed.
Thus, if you have experience with the use of Fitbit either yourself or in your practice, I’d certainly be interested in your experience.
This, according to a study by Ruth Brown and colleagues from Toronto’s York University, published in Medicine and Science in Sports and Exercise.
The study included 58 adult men and women of either normal weight (NW) or overweight (OW), who reported either attempting (WL) or not attempting weight loss (noWL)
Following 25 mins of exercise on a treadmill at either a moderate (60% HRmax) or a vigorous intensity (75% HRmax), participants were asked to estimated the number of calories they expended through exercise and create a meal that they believed to be calorically equivalent to the amount of calories they had just burnt.
Both the moderate and intense exercise groups were on average spectacularly wrong in their estimates.
In contrast, the active weight loss (WL) groups appeared to do far better at estimating energy consumption than the non-WL groups.
As an example, following vigorous exercise, the OW-noWL overestimated energy expenditure by 72%, and overestimated the calories in their food by 37%.
Although the WL groups did better, all groups showed a wide range of over and underestimation (-280 kcal to +702 kcal).
These findings show that while most people tend to over or underestimate caloric expenditure with exercise, overweight adults who are not attempting weight loss may be even more off the mark than others.
The most obvious solution would be to use some kind of monitor that does a better job of predicting calories consumed that just guessing.
That is of course, if overcompensating is not your goal (as in people who actually gain weight when they begin exercising).
For those interested in staying in energy balance, perhaps simply stepping on the scale regularly during the week should be enough.
For those interested in losing weight, they may need to be reminded that exercise (alone) is actually a pretty inefficient way to lose weight, so the calories burnt during exercise probably don’t matter all that much for weight management (despite all other benefits of exercise – its the calories you eat or drink that count).