Stop killing the elderly with kindness

Life partners for infinity (CC)

Update: the title of this post has been changed in response to a comment in the discussion.

This past winter I taught a course titled Physical Activity and Aging.  It was a fun course, and really drove home an issue that I’ve known for a while, but hadn’t previously given a lot of thought: the impact of aging is identical to the detraining that happens in response to reduced physical activity and/or increased sedentary behaviour.

Aging is associated with reduced fitness, weaker bones, reduced insulin sensitivity, reduced muscle strength, and reduced balance.  Lack of physical activity is also associated with all of those things.  This isn’t a coincidence – many (probably most) of the health impacts of aging are not really due to aging at all.

You see, there are 2 types of aging.  Eugeric aging, which you can think of as “true” aging. The stuff you simply cannot avoid as you get older (e.g. hearing loss, or reduced eyesight).

But there is also “pathogeric” aging, which refers to pathological aging (e.g. aging that’s unecessary/unhealthy).  Almost all the really scary things that we attribute to aging (weak bones, bones, heart, lungs, etc) falls into this category, and are much more likely to be caused by too little exercise/too much sitting, rather than aging itself.

I bring this up because I’m concerned that we are currently killing our elders with kindness.  We don’t let them carry their dishes to the sink (“Mom, sit down! I can get that!”).  We won’t let them do chores.  We worry if they have to go up and down stairs on a daily basis.  We get angry if they go for a walk without a chaperone.  We force them to sit to conserve their energy.  All of this flies in the face of evidence, and common sense. Picture the healthiest older adult that you know – do they spend their day sitting down, or do they spend their days walking, skiing, or dancing?  It’s not a coincidence.

If I were to take a healthy 20 year-old, force them to sit all day, and refused to let them do any physical labour out of fear they might hurt themselves, I would cause them to “age” extremely rapidly.  We call it detraining, and we’ve known about it for decades.  Put a healthy young person in a bed for less than a week and their metabolic health goes to hell – blood pressure increases, as does the amount of fat in the blood, while insulin sensitivity plummets by over 65% (details here).  And yet that’s the life that we often push upon the elderly out of fear that they might hurt/tire themselves out of they engage in too much physical activity (fun fact – exercise helps you sleep better, which is a good thing at all ages!).

What’s worse, there is often a vicious cycle – a person does less activity as they age, which causes reduced fitness.  That reduced fitness makes it harder to be active, so their activity levels drop more.  Which means fitness drops more.  And then muscle strength starts to slip. Which means even less activity, further reductions in fitness, and difficulties doing activities of daily living, or even living independently.  You get my point.  The good news? Even modest amounts of exercise result in increased functional and aerobic fitness, as well as improved metabolic health (details here).

We need to promote more, not less physical activity for our elders.  We should cheer them on when they decide to do physical chores, and encourage them to do more. The next time to consider telling your grandmother to sit down, think about whether that’s really in her best interest.


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Do mini-packaged snacks help you eat less junk?

Doritos-100kcalIn recent years countless food manufacturers have been “sub-packaging” their foods into smaller portions in an apparent effort to curb folks from overindulging. You can usually find 100 kcal multi-packs of chips, pretzels, chocolates, and all sorts of junk foods. Despite the very obvious negative environmental impact of all this excess packaging, what, if any, impact does such packaging have on people’s consumption.

Thankfully, Wansink and colleagues had previously published a paper in the journal Obesity investigating this very question.

I previously discussed another study by Wansink that essentially showed that when snacks are served in bigger bowls, people tend to eat more of their contents.

Thus, it would seem reasonable to think the reverse was also true in terms of small packages for snacks, as in the case with these hyper-packaged 100kcal bags of junk.

So the same authors sought to address this issue, and also to check if the effect on consumption of small packages differed between overweight and normal weight individuals.

A total of 42 undergraduate students participated in the simple study which basically had the participants snack on crackers while watching a sitcom – now THAT is what I call research!

Half of the participants were given one large 400-calorie package of crackers or a similar-sized package that had then been sub-divided into four smaller 100-calorie sub-packaged crackers. They were blinded to the purpose of the study.

After watching the show, the crackers not consumed by the participants were counted to calculate everyone’s caloric intake. Also, each participant was asked how many crackers they think they consumed.

Turns out, overweight participants ate significantly more crackers when eating from one large package than from four small packages. In fact, they consumed more than double the number of calories with the bigger package: 384 calories versus 176 calories.

Surprisingly, there was no difference in consumption between package conditions among the normal-weight participants.

Despite this difference in consumption, what is odd is that all groups (small package and big package, overweight and normal weight) underestimated how many crackers they had eaten by more than 60%!

This suggests that the smaller packaging doesn’t make people more accurate at keeping track of what they ate.

So why the difference between overweight and normal weight participants?

The authors suggest the following:

“Obese people were more likely to rely on external cues to stop eating, [and thus] the perception of package count might play a crucial role for overweight participants in determining their food intake.”



Wansink, B., Payne, C., & Shimizu, M. (2011). The 100-Calorie Semi-Solution: Sub-Packaging Most Reduces Intake Among The Heaviest Obesity DOI:10.1038/oby.2010.306

Category: nutrition, Obesity Research, Peer Reviewed Research | 5 Comments

Why you crave tomato juice on an airplane

tomato juiceI’m writing this seated on a plane heading to San Francisco. We’ve been in the air for under an hour, and the drink cart is just starting to make its way down the aisle. As the cart rolls nearer I’m forced to decide what drink I’ll be having. Since the cups are miniscule, and the liquid is largely displaced by ice cubes if one’s not quick enough to add “no ice, please” to the order, the decision is critical.

Despite the fact that I never drink tomato juice on the ground, I’m once again craving the drink in mid air. In fact, on the very first flight I took as a kid – from Athens, Greece to Toronto back in 1991 – I distinctly remember ordering tomato juice. Now, why would a 10-year old kid crave tomato juice? And why am I now having the same craving?

It has been known for some time that there exists overlap between our senses in how we perceive the world. For instance, it is well-established that the visual appearance of food influences the perception of flavour. Ever made the error of having three things on your plate of broadly the same colour? There’s just something very unappetising about it, and the flavour never seems as rich as expected. The role of our olfactory sense in the perception of flavour is well illustrated by the blandness of most food when we have a cold and are noses are congested. Differing textures are also helpful in making food more appetising.

So what about the flight experience might be playing havoc with our perception of taste and thus our craving for certain flavours. The answer, according to some recent research, appears to be cabin noise.

In the study, Yan and Dando assessed the effect of loud audio stimulation on the perception of the five basic tastes.

A total of 48 men and women evaluated multiple standardized solutions for perception of sweet, salty, sour, bitter, and umami flavours, on a validated scale while in silence (condition A) or an environment that replicated conditions found during airplane flight and landing (condition B). Specifically, cabin noise was recreated from actual airplane cabin noise recordings, delivered to participants at 80 to 85 dB through high-definition headphones.

And what did the research reveal?

First, noise that one might experience onboard an airplane seems not to affect our perception of salty, bitter, and sour flavours.

However, exposure to loud noise caused a pronounced suppression of sweetness intensity across all concentrations measured. Ever noticed how all pop drinks taste like their diet (low or no-sugar) equivalents while in the air?

Conversely, loud noise was found to increase the perceived intensity of umami flavour, found in foods and drinks containing monosodium glutamate (MSG).

Thus, the popularity of umami-rich drinks such as tomato juice onboard airplanes may be the combined result of enhanced umami taste and dulled sweet taste.

These findings may also explain the consistently poor ratings of airplane food. Then again, the cardboard that passes for chicken on planes is likely to taste just as awful on the ground as it does at 30,000 feet.

And finally, the level of noise at restaurants may also influence the flavours perceived in the foods served. Theoretically, a loud restaurant would do well to serve umami-rich foods, but focus less on desserts and sweets.

Or you could just bring industrial-strength ear plugs with you everywhere and avoid noise affecting your meal altogether.


Reference: Kimberly S. Yan and Robin Dando. 2015.  A Crossmodal Role for Audition in Taste Perception. Journal of Experimental Psychology: Human Perception and Performance.
Advance online publication.

Category: News, nutrition, Obesity Research, Peer Reviewed Research | 2 Comments

Juice ≠ Fruit (!!!)

orange juice

Word emerged last week that Health Canada was re-considering whether it should continue to view a serving of juice (125 ml) as being equivalent to a half cup of fresh/frozen fruit.  I think this would be a wonderful development, and I believe that my own personal experience helps to explain why.

While I was growing up, I drank a lot of juice.  Over a litre a day.  During my university days, I often bought 10 or more litres of juice in a given trip to the grocery store. Whenever my roomates poked fun at all that juice consumption (which was often), I would point to the sticker on the carton stating that it was the nutritional equivalent of eating a serving of fruit.  The calories shouldn’t count, because…. fruit.

That was then.  My thinking has changed somewhat in the intervening years.  Now, I realize that drinking a small bottle of orange juice is the equivalent of eating 6 oranges, which would strike most people as excessive.  In contrast, the amount of juice in a single orange is rather pathetic:

The amount of juice in one orange

Further, a glass of Tropicana has more calories than an identical glass of Coke or Pepsi.

Calories & Sugar in 12 ounces of Coca-Cola, Pepsi, and Tropicana

And what about smoothies?  As I’ve said in the past:

Even a freshly made fruit smoothie is still pretty refined when compared to the fruit itself. It takes a fair amount of energy and chopping (not to mention a fancy modern blender) to get a pineapple to the point that you can consume it through a straw.  You can think of a fruit smoothie as essentially a piece of blueberry pie in a glass – at least in the pie the blueberries aren’t liquefied (seriously – an original size strawberry raspberry banana smoothie at Jamba Juice has more calories and more sugar than a piece of homemade blueberry pie). Smoothies may be a lot less refined than Twinkies, but they’re not all that far from Nutella or peanut butter.

So let’s all hope that Health Canada decides to make the common sense move, and stop considering juice and fruit to be nutritionally equivalent.


Category: News | 2 Comments

Burger Loss

Today’s post comes from friend and colleague Dr Jamie Burr, and was originally posted on his own blog, available here.

Last month in PEI we “celebrated” what has become an annual ritual known as Burger Love. If you are not familiar with the concept, it is an event sponsored by various government industries and the PEI beef farmers to promote local meat consumption. Restaurants across the island prepare extravagant burgers, and after eating them (at $15/piece) the patrons rank them online so that a winner is crowned at the end of the month. Let me say upfront, that I don’t think this is a bad promotion overall – and for full disclosure I will admit that I tried a burger or two myself (usually shared with my wife) and they were quite tasty.

Like anything, however, Burger Love may best be enjoyed in moderation. Whether or not moderation was practiced is up for debate, but given that 145,527 burgers (65,068 lb of beef) were sold, at a rate of almost 5,000/day in a province of only 150,000 people, I find it hard to make that case. Compounding this effect, the Guinness record attempt for 24hr burger consumption saw 9,000 burgers consumed in this time. I’m not certain that this is something we ought to be particularly proud of – but my opinion may differ from the large majority.

As a health/performance physiologist, what jumped out at me was the size and relative caloric density of these burgers, many of which contain multiple meat paddies, and sugar/fat based glazes, sauces and toppings. Using the Dieticians of Canada “eaTracker” software (link) I calculated an average Burger Love meal to fall anywhere between 1500 to 2500 kcal ranging from the somewhat modest to more lavish creations. No big deal though- you can just exercise a little more than normal and burn it off….right?


Through the month of burger lovin, it occurred to me that the caloric math was probably not at the forefront of many diners’ minds nor did it play prominently in the decision process of where or what to eat. So, for the sake of illumination, I thought it helpful to show just how much of an impact a single burger love could have on caloric balance, and how long you would need to exercise to get back to a zero-gain. For the following calculations I have made a few assumptions to represent the “average” person, which errs on the side of conservatism. Our fictitious person is a 30yr old male, of near average height (5’11”) and weight (170lb).

At a modest pace of 3mph, it would take approximately 420min (7hrs) of continuous walking. But perhaps that’s a silly comparison, because many fit 30-somethings would have no problem “upping” the intensity. If our burger-lover were to jog at a moderate pace it would only take him 280 min (>4.5hr) or if he ran at 7mph, he could cut the time of burger loss to a mere 160 min (2.7hr). Obviously, running is not for everyone, perhaps a leisurely 3hr cycle (at 23-26km/h) is more your style. Prefer to swim? No problem, at a moderate pace you could burn off half of a burger in a mere 160 min (2.6hr).

So, does this mean you shouldn’t ever eat a hamburger? Of course not, you’ve got enjoy life and good food can certainly contribute to mental (and even physical) well-being. But understanding the idea of caloric balance (even if it’s as simple as calories in vs. calories out) might be an important consideration. But on the bright side, you’ve got a whole 11 months to burn it off before next year. Unfortunately, we might need it.

Interested in figuring out more about the energy costs of certain physical activities? Check out the American College of Sports Medicine “Compendium of Physical Activities” which can be found here in hard copy, or here as an online tool.

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30% of people with a “healthy” BMI are actually obese

scaleAlthough I’ve discussed this issue a number of times over the years, every now and then a new study comes out that provides further evidence of the limitations of body mass index (BMI) as a measure of health, or even adiposity (level of fat in the body).

Recall that BMI is the most common metric used to assess body weight status, and to identify the presence of overweight and obesity. While it is great when used in epidemiological studies across thousands of people, it’s a pretty lousy measure on an individual basis. So why does it keep being used? Its relatively easy and inexpensive to measure height and weight – hence, the measure persists in clinical practice.

In this cross-sectional study the authors assessed the BMI, body fat percentage, and cardiometabolic risk factors of 6123 (924 lean, 1637 overweight and 3562 obese classified according to BMI) Caucasian subjects (69% females) between the ages of 18 and 80 years.

What did they find?

First, 29% of subjects classified as normal weight and 80% of individuals classified as overweight according to BMI had a body fat percentage within the obese range. Thus, on an individual basis BMI tends to consistently underestimate a person’s adiposity. This data implies that there are many individuals who don’t weigh that much on an absolute scale, but a large proportion of their weight is composed of fat tissue. These are people who may look thin, but tend to be soft, with little muscle tone. In a clinical setting, these folks may easily be overlooked by their physician due to their “normal weight.”

Conversely, approximately 5% of individuals classified as overweight and 0.2% of those classified as obese by BMI actually had low levels of fat mass. These individuals would be the bodybuilders of the bunch – high absolute body weight that is composed mostly of muscle mass. This is often the line of argument used to illustrate how ineffective BMI is at measuring adiposity. And yet, as I’ve criticized before, the misclassification in this direction appears to occur only rarely. This simply suggests there are simply few body builders around. More importantly, any physician should be able to conclude that the patient in front of them with a BMI of 31 kg/m2 is not actually obese when their biceps are bigger than their waist.

Finally, when compared to individuals who were actually lean (both on BMI and body fat), those with a high levels of adiposity, regardless of their BMI (normal weight, overweight or obese BMI) had poorer cardiometabolic profiles, including elevated blood pressure, blood glucose and lipid levels, as well as markers of systemic inflammation.

So how can a physician determine whether a patient with a normal or overweight BMI is actually obese? Measuring waist circumference certainly seems to help. This one measure can help distinguish those with a low versus high adiposity despite similar BMIs.

Even better, physicians could start paying less attention to weight or adiposity altogether, and evaluate more relevant markers of a patient’s health, including metabolic factors, psychological status, mobility, etc.


Reference: Gomez-Ambrosi et al. Body mass index classification misses subjects with increased cardiometabolic risk factors related to elevated adiposity. International Journal of Obesity (2012) 36, 286–294; doi:10.1038/ijo.2011.100; published online 17 May 2011

Category: News, Obesity Research, Peer Reviewed Research | 15 Comments