109 posts · 86,495 views
Travis Saunders and Peter Janiszewski are PhD students in Exercise and Health Physiology at Queen's University in Ontario, Canada. Their research focuses on obesity, body composition, physical activity, nutrition and metabolic health.
Obesity Panacea
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- May 2, 2012
- 02:48 PM
- 106 views
Sedentary behaviour – one definition to rule them all
by Travis Saunders, MSc in Obesity Panacea
Exciting news – this week the Sedentary Behaviour Research Network published an updated definition of the terms “sedentary” and “sedentary behaviour” in French and English in the journals Applied Physiology, Nutrition and Metabolism and Movement & Sport Sciences – Science & Motricité.
In brief, the new definition states that to be engaging in “sedentary behaviour”, you must meet three very basic criteria:
You must be expending very little energy (≤1.5 Metabolic equivalents)
You must be sitting or lying down
You must be awake... Read more »
Sedentary Behaviour Research Network. (2012) Letter to the Editor: Standardized use of the terms "sedentary" and "sedentary behaviours". Applied physiology, nutrition, and metabolism . PMID: 22540258
- April 4, 2012
- 02:58 PM
- 129 views
Sitting for just a couple hours has measurable (and negative) health impact
by Travis Saunders, MSc in Obesity Panacea
Last week a fascinating study was published by SBRN member David Dunstan and colleagues in Australia, which examined the acute (e.g. short-term) impact of uninterrupted sitting on metabolic health. In this new study, individuals with overweight or obesity were asked to perform 3 separate conditions in random order.
Uninterrupted sitting – participants sat for 5 consecutive hours
Sitting plus light intensity breaks – similar to the uninterrupted sitting condition, except that participants had a 2 minute walk break at a light intensity every 20 minutes throughout the day
Sitting plus moderate intensity breaks – similar to the light intensity breaks condition, except that the breaks were at a moderate intensity
... Read more »
Dunstan, D., Kingwell, B., Larsen, R., Healy, G., Cerin, E., Hamilton, M., Shaw, J., Bertovic, D., Zimmet, P., Salmon, J.... (2012) Breaking Up Prolonged Sitting Reduces Postprandial Glucose and Insulin Responses. Diabetes Care. DOI: 10.2337/dc11-1931
Nygaard, H., Tomten, S., & Høstmark, A. (2009) Slow postmeal walking reduces postprandial glycemia in middle-aged women. Applied Physiology, Nutrition, and Metabolism, 34(6), 1087-1092. DOI: 10.1139/H09-110
- March 27, 2012
- 10:40 AM
- 153 views
Canada Releases Physical Activity and Sedentary Behaviour Guidelines for Kids Aged 0-4
by Travis Saunders, MSc in Obesity Panacea
Until recently, only one set of physical activity guidelines was available for children under the age of 5 years (National Association for Sport and Physical Education, 2009). These guidelines were useful recommendations for parents and caregivers with advice on healthy living, but were informed largely on expert consensus and not by the rigor of a systematic review. Last year, Australia and the United Kingdom (UK) were the first to release evidence-based guidelines and recommend that preschoolers be physically active for at least 180 minutes per day (Department of Health and Ageing, Australia 2011; Start Active, Stay Active, United Kingdom, 2011). The full guidelines can be found here and here. However, a systematic review was still not publicly available to inform the development Canadian guidelines for this age group.... Read more »
Tremblay MS, LeBlanc AG, Carson V, Choquette L, Connor Gorber S, Dillman C, Duggan M, Gordon MJ, Hicks A, Janssen I.... (2012) Canadian Physical Activity Guidelines for the Early Years (aged 0–4 years). Applied Physiology, Nutrition and Metabolism. info:/
- January 19, 2012
- 10:00 AM
- 287 views
30 Years of Aging vs 3 Weeks of Bed Rest – Which is Worse For Aerobic Fitness?
by Travis Saunders, MSc in Obesity Panacea
I recently came across a very interesting study published in Circulation in 2001. In it, authors Darren McGuire and colleagues perform the 30-year follow-up on a group of 5 men who had taken part in the Dallas Bed Rest and Training Study (DBRTS). The DBRTS took place in 1966, when all 5 men were healthy 20 year-olds. They were assessed extensively at baseline, following 3 months of bed rest, and following 8 weeks of physical training. In 1996 these same 5 men were re-assessed, allowing the researchers to compare the influence of 3 weeks of bed rest and 30 years of aging on markers of fitness.... Read more »
McGuire DK, Levine BD, Williamson JW, Snell PG, Blomqvist CG, Saltin B, & Mitchell JH. (2001) A 30-year follow-up of the Dallas Bedrest and Training Study: I. Effect of age on the cardiovascular response to exercise. Circulation, 104(12), 1350-7. PMID: 11560849
- December 16, 2011
- 11:55 AM
- 1,219 views
Contributors to the Pediatric Obesity Epidemic Part 5: Risk Factors I Missed
by Travis Saunders, MSc in Obesity Panacea
Today we will look at other potential contributors to the pediatric obesity epidemic which I didn’t include in my paper. There are a few reasons for that – some risk factors are ones that I just felt didn’t have much evidence behind them, others were similar to ones that were included, and some just didn’t fit within the space constraints (since this paper was originally written for my comprehensive exams, it was limited to 15 pages).... Read more »
Saunders, T. (2011) Potential Contributors to the Canadian Pediatric Obesity Epidemic. ISRN Pediatrics, 1-10. DOI: 10.5402/2011/917684
- December 15, 2011
- 09:43 AM
- 1,206 views
Contributors to the Pediatric Obesity Epidemic Part 4: Adult Obesity, and Relative Contributions of All Risk Factors
by Travis Saunders, MSc in Obesity Panacea
In Part 1 we examined the impact of changes in physical activity and sedentary behaviour, in Part 2 we looked at changes in food intake, and in Part 3 we looked at sleep, breastfeeding, maternal age and pollution. Today we look at the evidence (or lack thereof) linking adult obesity with the pediatric obesity epidemic, then examine the relative contributions of all of the risk factors we’ve discussed so far.... Read more »
Saunders, T. (2011) Potential Contributors to the Canadian Pediatric Obesity Epidemic. ISRN Pediatrics, 1-10. DOI: 10.5402/2011/917684
- December 14, 2011
- 09:00 AM
- 2,333 views
Contributors to the Pediatric Obesity Epidemic Part 3: Sleep, Maternal Age, Pollution & Breastfeeding
by Travis Saunders, MSc in Obesity Panacea
In Part 1 we examined the impact of changes in physical activity and sedentary behaviour, and in Part 2 we looked at changes in food intake. Today we look at the evidence (or lack thereof) linking sleep, pollution, maternal age and breastfeeding with the pediatric obesity epidemic.... Read more »
Saunders, T. (2011) Potential Contributors to the Canadian Pediatric Obesity Epidemic. ISRN Pediatrics, 1-10. DOI: 10.5402/2011/917684
- December 8, 2011
- 10:00 AM
- 284 views
Dear Newspapers: Individual Studies Do Not Exist In A Vacuum
by Travis Saunders, MSc in Obesity Panacea
Just because one study finds a relationship between A and B, does not mean that other studies will be able to replicate that finding, or that it will extend to other situations. On the face of it, this seems like an incredibly obvious statement. And yet it’s something that newspapers often forget, and which I think could have some very negative consequences.... Read more »
Goldfield, G., Kenny, G., Hadjiyannakis, S., Phillips, P., Alberga, A., Saunders, T., Tremblay, M., Malcolm, J., Prud'homme, D., Gougeon, R.... (2011) Video Game Playing Is Independently Associated with Blood Pressure and Lipids in Overweight and Obese Adolescents. PLoS ONE, 6(11). DOI: 10.1371/journal.pone.0026643
Carson, V., & Janssen, I. (2011) Volume, patterns, and types of sedentary behavior and cardio-metabolic health in children and adolescents: a cross-sectional study. BMC Public Health, 11(1), 274. DOI: 10.1186/1471-2458-11-274
- September 27, 2011
- 10:00 AM
- 566 views
World’s First Systematic Review On Sedentary Behaviour & Health in School-Aged Children
by Travis Saunders, MSc in Obesity Panacea
Some exciting news this week - the world’s first systematic review on the relationship between sedentary behaviour and health in school-aged children has just been published online in the International Journal of Behavioural Nutrition and Physical Activity. I am one of 8 authors on the review (nestled nicely in the middle), which was created to inform the Canadian Sedentary Behaviour Guidelines, released earlier this year.... Read more »
Tremblay, M., LeBlanc, A., Kho, M., Saunders, T., Larouche, R., Colley, R., Goldfield, G., & Connor Gorber, S. (2011) Systematic review of sedentary behaviour and health indicators in school-aged children and youth. International Journal of Behavioral Nutrition and Physical Activity, 8(1), 98. DOI: 10.1186/1479-5868-8-98
- December 1, 2010
- 12:10 PM
- 798 views
Animal obesity: canary in the coal mine?
by Travis Saunders, MSc in Obesity Panacea
There are a number of factors, both behavioural and environmental, which are thought to play important roles in the current epidemic of obesity. These range from things like increased soft-drink consumption and decreased physical activity, which are at least nominally under our personal control, to more external factors like viruses, light pollution, and environmental contaminants, over which we have little or no control. How much of a role do these external factors play in the obesity epidemic? No one knows. But if these external factors are playing a role in the human obesity epidemic, then we would also expect to see similar increases in body weight and obesity rates among animals who live with or near humans, since they would be exposed to many of these same factors. To this end, a fascinating new paper by Yann Klimentidis and colleagues examines the body weight and risk of obesity in 8 different species, and the results suggest that external factors may be playing a larger role in obesity rates that previously thought. ... Read more »
Klimentidis, Y., Beasley, T., Lin, H., Murati, G., Glass, G., Guyton, M., Newton, W., Jorgensen, M., Heymsfield, S., Kemnitz, J.... (2010) Canaries in the coal mine: a cross-species analysis of the plurality of obesity epidemics. Proceedings of the Royal Society B: Biological Sciences. DOI: 10.1098/rspb.2010.1890
- November 22, 2010
- 01:35 PM
- 1,021 views
The Obesity Paradox Revisited
by Travis Saunders, MSc in Obesity Panacea
As Peter and I discuss frequently here at Obesity Panacea, the relationship between body weight and health is not always as neat and tidy as you might expect (For all the details, check out Peter’s 5-part series on metabolically healthy obesity). A recent paper published in the International Journal of Obesity by Drs DK Childers and David Allison examines a number of these issues, and suggests ways that they may be at least partially resolved.
In the intro to this new paper, the authors point out 3 confusing issues surrounding the relationship between body weight and health:
1. The relationship between body mass and mortality in epidemiological studies is “U-shaped” – high health risk for individuals with a body mass that is very high or very low, and low risk for individuals with intermediate body mass (e.g. 18-28 kg/m2 or so, ... Read more »
Childers, D., & Allison, D. (2010) The ‘obesity paradox’: a parsimonious explanation for relations among obesity, mortality rate and aging?. International Journal of Obesity, 34(8), 1231-1238. DOI: 10.1038/ijo.2010.71
- November 15, 2010
- 01:04 PM
- 1,014 views
Can obesity surgery for mothers prevent obesity in their children?
by Travis Saunders, MSc in Obesity Panacea
…And we’re back! After a month in exile from the blogging world my comprehensive exams are done!… for now. Assuming that my committee finds my answers satisfactory I will move on to an oral exam sometime between now and the holiday season. The good news is that I have read a ton of papers in the past few months (probably somewhere north of 200) so I’ve found plenty of interesting things to blog about well into the new year!... Read more »
Kral, J., Biron, S., Simard, S., Hould, F., Lebel, S., Marceau, S., & Marceau, P. (2006) Large Maternal Weight Loss From Obesity Surgery Prevents Transmission of Obesity to Children Who Were Followed for 2 to 18 Years. PEDIATRICS, 118(6). DOI: 10.1542/peds.2006-1379
- September 10, 2010
- 10:30 AM
- 959 views
How does TV watching increase health risk?
by Travis Saunders, MSc, CEP in Obesity Panacea
Earlier this year I came across a very interesting study on Dr Yoni Freedhoff’s blog Weighty Matters. Yoni described a new study published in the American Journal of Public Health which suggests that the amount of commercial television (e.g. television with advertisements) that children watch before the age of 6 is associated with increased body weight 5 years down the road, even after adjustment for other important variables including physical activity, socio-economic status and mother’s BMI. In contrast, watching non-commercial television (DVD’s or TV programs without commercials) showed no association with body weight. The data was self-reported, but nonetheless these are pretty interesting findings, and suggest that television commercials are likely an important mechanism linking screen time with obesity risk.... Read more »
Zimmerman, F., & Bell, J. (2009) Associations of Television Content Type and Obesity in Children. American Journal of Public Health, 100(2), 334-340. DOI: 10.2105/AJPH.2008.155119
- September 7, 2010
- 01:07 PM
- 923 views
Do the Health Benefits of Cycling Outweigh the Risks?
by Travis Saunders, MSc, CEP in Obesity Panacea
Regular readers of Obesity Panacea will know that I am a huge fan of active transportation, which entails commuting via active means (e.g. walking, cycling, or taking public transit rather than driving). But when I talk with my friends about the many health and societal benefits of active commuting by bicycle, they almost always bring up the fact that they value their lives too much to risk cycling on busy city streets. This is obviously not a trivial concern – here in Ottawa there were three cycling deaths in a three day period in August, and another tragic death occurred earlier this week (although in at least 2 of those accidents, it may have been cyclist errors which resulted in the accidents).... Read more »
Johan de Hartog J, Boogaard H, Nijland H, & Hoek G. (2010) Do the health benefits of cycling outweigh the risks?. Environmental health perspectives, 118(8), 1109-16. PMID: 20587380
- September 1, 2010
- 01:00 PM
- 1,577 views
What Hurts Fitness More: 30 Years of Aging or 3 Weeks of Bed Rest?
by Travis Saunders, MSc, CEP in Obesity Panacea
I recently came across a very interesting study published in Circulation in 2001. In it, authors Darren McGuire and colleagues perform the 30-year follow-up on a group of 5 men who had taken part in the Dallas Bed Rest and Training Study (DBRTS). The DBRTS took place in 1966, when all 5 men were healthy 20 year-olds. They were assessed extensively at 3 different time points: baseline, following 3 months of bed rest, and following 8 weeks of physical training. In 1996 these same 5 men were assessed for a fourth time, allowing the researchers to compare the influence of 3 weeks of bed rest and 30 years of aging on markers of fitness.... Read more »
McGuire DK, Levine BD, Williamson JW, Snell PG, Blomqvist CG, Saltin B, & Mitchell JH. (2001) A 30-year follow-up of the Dallas Bedrest and Training Study: I. Effect of age on the cardiovascular response to exercise. Circulation, 104(12), 1350-7. PMID: 11560849
- June 25, 2010
- 11:23 AM
- 1,361 views
Grow More Fat and Improve Metabolic Health: Insights from TZD Treatmen
by Travis Saunders, MSc in Obesity Panacea
By now, readers of Obesity Panacea have hopefully learned that excess weight is not directly predictive of health risk, and that excess fat mass is not in itself unhealthy. Recall that approximately 30% of individuals who are classified as obese by their body weight turn out to be metabolically healthy, and in fact seem not to get much metabolic benefit (or may even get worse) when they lose weight. Also consider that individuals who have NO fat tissue (e.g. lipodystrophy) have extremely elevated metabolic risk factors, meanwhile others who can apparently indefinitely grow more fat mass (multiple symmetric lipomatosis - think Michelin man) have metabolic profiles we'd all like to have. Read the rest of this post... | Read the comments on this post...... Read more »
McLaughlin, T., Liu, T., Yee, G., Abbasi, F., Lamendola, C., Reaven, G., Tsao, P., Cushman, S., & Sherman, A. (2009) Pioglitazone Increases the Proportion of Small Cells in Human Abdominal Subcutaneous Adipose Tissue. Obesity. DOI: 10.1038/oby.2009.380
- June 23, 2010
- 12:20 PM
- 1,313 views
Are High Glycemic Index Carbs Worse Than Saturated Fat?
by Travis Saunders, MSc in Obesity Panacea
Most people know that consuming too much fat, and especially saturated fat, is bad for your health. That's why there has been a concerted push for several decades to get people to reduce the amount of saturated fat that they consume, and to replace it with complex carbohydrates. Now unfortunately people often misinterpret that to mean that fat is evil, but carbs are ok. This is problematic since consuming too many simple carbs is also likely to increase the risk of obesity, diabetes, and cardiovascular disease - exactly what we are trying to prevent in the first place. So this raises the important question - in order to minimize the risk of heart disease, is it better to reduce the intake of saturated fat, or the intake of simple carbs? An interesting new study in the American Journal of Clinical Nutrition examines this issue and while it doesn't provide a definitive answer, it suggests that refined carbs are pretty bad indeed.... Read more »
Hu FB. (2010) Are refined carbohydrates worse than saturated fat?. The American journal of clinical nutrition, 91(6), 1541-2. PMID: 20410095
Jakobsen MU, Dethlefsen C, Joensen AM, Stegger J, Tjønneland A, Schmidt EB, & Overvad K. (2010) Intake of carbohydrates compared with intake of saturated fatty acids and risk of myocardial infarction: importance of the glycemic index. The American journal of clinical nutrition, 91(6), 1764-8. PMID: 20375186
- June 14, 2010
- 11:15 AM
- 1,168 views
Self-report vs direct measures - new podcast!
by Travis Saunders, MSc in Obesity Panacea
Regular readers know that that Peter and I do a semi-regular podcast on obesity-related issues. This week, I have a discussion with psychology researcher (and fellow ScienceBlogger) Jason Goldman. For the uninitiated, self-report data refers to information that people provide themselves - questionnaires and interviews are very common examples. This is in contrast to direct measurement, which is exactly what it sounds like - researchers measuring your height and weight themselves, etc. The podcast was inspired by a recent conversation where I bemoaned a press release which failed to acknowledge the limitations of self-report data, which I felt could lead to misleading conclusions.... Read more »
Schwarz, N. (1999) Self-reports: How the questions shape the answers. American Psychologist, 54(2), 93-105. DOI: 10.1037//0003-066X.54.2.93
- June 4, 2010
- 11:45 AM
- 1,468 views
Increased Physical Activity Prevents the Accumulation of Abdominal Fat
by Travis Saunders, MSc in Obesity Panacea
One of the most interesting things about exercise is that it results in important health improvements even in the absence of weight loss. For example, just a single session of exercise can result in improved insulin sensitivity, increased levels of HDL cholesterol (aka the "good" cholesterol) and reductions in plasma triglyceride levels - all tremendously important markers of disease risk. In addition to these metabolic changes, new research by our friend and former labmate Lance Davidson suggests once-again that exercise can also prevent the accumulation of abdominal fat, independent of changes in overall body fat percentage.... Read more »
Davidson, LE, Tucker, L, & Peterson, T. (2010) Physical Activity Changes Predict Abdominal Fat Change in Midlife Women. Journal of Physical Activity and Health. info:/
- June 2, 2010
- 11:41 AM
- 1,169 views
New Publication: Big Breasts, An Indicator of Dangerous Fat Deposition?
by Travis Saunders, MSc in Obesity Panacea
In June of last year, I discussed the results of a large epidemiological study in women that showed that women with larger breasts have an increased risk of developing type-2 diabetes.
As soon as Travis and I read this study, we knew we had to do a follow-up study of our own to see if this finding was simply spurious or if there was actually something to large breasts that indicated health risk - beyond that explained by obesity per se.
The project that Travis and I began over a year ago has culminated in both a hot-off-the-press publication in the journal Obesity, as well as my presentation at this year's Obesity Society meeting in Washington D.C.
In the study, we used body composition data acquired through MRI on about 100 premenopausal women to directly quantify breast size. By using MRI data we significantly improved the methodology used by the authors of the original study on breast size and diabetes risk, who relied on over 20 year recall of cup size as their key measure.
First, we sought to examine if breast tissue volume was associated with any cardiometabolic risk factors, such as glucose tolerance (a known antecedent to type 2 diabetes) and various blood lipids. Since the original authors found an association between cup size and diabetes risk, we expected to find an association between breast volume and cardiometabolic risk factors.
What did we actually find? Read the rest of this post... | Read the comments on this post...... Read more »
Janiszewski, P., Saunders, T., & Ross, R. (2009) Breast Volume is an Independent Predictor of Visceral and Ectopic Fat in Premenopausal Women. Obesity. DOI: 10.1038/oby.2009.336
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