Diabetes Canada Guidelines 2018 - Physical Activity

There is a ton of great, new information in the 2018 Diabetes Canada Physical Activity guidelines chapter.  Here are some of the highlights:


1. Avoid prolonged sitting. Try to get up briefly every 20 to 30 minutes.  Bluntly put, this is because we now know that habitual, prolonged sitting is associated with an increase risk of death and major cardiovascular events (eg heart attack).

2. While it is still recommended to engage in 150 minutes per week of aerobic exercise and at least 2 sessions per week of resistance exercise if possible, it is now recognized that smaller amounts of activity still provides some health benefits. Something is better than nothing!

3.  Make use of strategies that increase motivation, such as setting specific physical activity goals, and using self monitoring tools (eg a pedometer that counts steps). (My editorial comment - some of these devices can also remind you to get up if you've been sitting for too long.)

4.  Medical clearance: It was previously recommended that anyone with diabetes who is about to begin a program more vigorous than walking should have medical clearance first.  This has been relaxed a little - now, this need for clearance is more focussed on middle aged and older people who wish to undertake prolonged or very vigorous exercise, and of course, anyone with symptoms suggestive of cardiovascular disease.

People with more advanced diabetic eye disease should be treated and stabilized before vigorous exercise, and people with severe diabetic nerve disease in their feet/legs should inspect their feet daily and wear appropriate footwear.   It is also recommended to ideally see a qualified exercise specialist before starting strength training (eg weights) to avoid injury.

5.  There is a great list of suggested strategies to help people with type 1 diabetes reduce the risk of lows with exercise.


Bonus Practical Stuff: 

Resources for people with diabetes: (scroll down to Exercise) - including info on how to plan and maintain physical activity, videos on resistance exercises, and more!

Resources for health care providers: under 'Management' - scroll down to 'Physical Activity and Diabetes' - tools including how to write an exercise prescription


Enjoy - and have fun!

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www.drsue.ca © 2018

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Sudden Death During Triathlons

Ever think that a triathlete seems invincible? They can swim, they can ride, they can run…. 

It turns out that the risk of sudden death during a triathlon is higher than the risk of sudden death in the general population.  

A recent study is the first to collect data on sudden deaths during triathlons.  (Triathlons consist of a swim, followed by cycling, followed by a run.)  The study reviewed race related deaths during 30 years of triathlons in USA, with data from over 9 million participants.  They identified 135 deaths, for a risk of death of 1.74 per 100,000 participants.  

Perhaps surprisingly, most of the sudden deaths and cardiac arrests (90) occurred during the swim (which starts the race), with 7 during cycling, 15 during the run, and 8 during the post race recovery.  Men age 60 and older were at the highest risk of death at 18.6 per 100,000.  There were also 15 trauma related deaths during cycling. 

Of the 135 deaths, 61 autopsies were performed.  At least 18 of these deaths were due to narrowing of the arteries of the heart.

Why do so many of these sudden deaths occur during the swim, which is at the start of the race?  This may be due to the adrenaline rush at the start of the race increasing the risk of heart arrhythmias, crashes in the water, and/or difficulty in identifying events and initiating rescue, defibrillation and CPR.  This contrasts with data in marathoners (a race of running only), which suggests that sudden deaths in marathons most commonly occur at the end of the race.  Cardiovascular disease accounts for the the majority of marathon-related cardiac arrests.

Bottom Lines:  

1.  Screening for cardiovascular disease when appropriate is important, and triathletes are no exception.  

2.  Organization of races to reduce risk is important: eliminating mass swim starts, and having coordinated safety responses to identify and help people in trouble are key.

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Children's Fitness Falls In Summer

You'd think that summertime would be a time of peak physical fitness for kids, right?  The weather is great, the days are long, school is out, and there is nothing but time for just being a kid... running, jumping, playing all day long.

Think again.

A study in the UK, which was presented recently at the Congress of the European College of Sport Science, tracked the fitness of over 400 children for just over a year.  They found that at the start of the school year in September, kids were not able to run as far as they could at the end of the prior school term in June.   They also found that body mass index (BMI) climbed between June and September (though BMI percentile would be the more appropriate measure).  The decrease in fitness was particularly evident in kids from areas of lower socioeconomic status.

These findings suggest that kids may be more often spending their summer holidays being inactive, perhaps in front of the TV or video games rather than being active in the great outdoors.  Active child care activities during the summer (eg summer camps) can be costly, so kids from less affluent homes may have less access to organized activities.

If you're having trouble keeping your young ones active this summer, here are some suggestions:

• Limit screen time.  Kids will find other things to do that are likely more active.
• Check out your local community facilities, parks and pools to see what is on offer.  
• Enjoy the warm weather and bright evenings with a family walk or bike ride! 
• Consider signing your kids up for a race (eg family fun run, or even a kids' triathlon!) and get them engaged to train for it.  

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www.drsue.ca © 2017

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An 86 Year Old Ironman Inspiration!

In line with last week's post about the amazing Olympic athletes, here's a woman who inspires me to the ends of the earth - meet Madonna Buder, who holds the world record for the oldest person to ever complete an Iron Man triathlon, at the age of... 82!

Buder caught the triathlon bug a little later in life, completing her first triathlon at age 52 and her first Ironman at age 56.  She has completed over 325 triathlons, including 45 Ironman distances (an Ironman is a 3860m swim, 180km bike, followed up by a 42km marathon run).

Now 86 years old, Buder is an inspiration to athletes everywhere, and was even featured in a Nike ad that was aired during the Olympics.

Way to go!!  Thanks so much to my friend Chantelle for telling me about this amazing woman.

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Olympic Games - Best Weight At All Sizes

It has been a real inspiration and thrill to watch the elite athletes of the world compete at the Rio 2016 Summer Olympic Games.  Over the last couple of weeks, we have enjoyed watching a wide range of sports, from swimming, to basketball, to gymnastics, to track & field, and so much more.

Take a moment and consider the variation in body shapes and sizes amongst this year's incredible athletes:

Each of these sports have a fierce demand for the highest level of physical ability, the nature of which is unique to each individual sport.  Some require intense upper body strength, while others are more lower body oriented; some high anaerobic capacity; others are all about endurance.

I see a similar diversity in body shape and size in the athletes in my clinical practice as an endocrinologist: marathoners, crossfitters, cyclists, swimmers, football players, and so many others.  The sad reality is that those who are of larger body size will often tell me that they feel judged and assumed to be inactive or 'lazy' based on their shape and size by people who have absolutely no idea what that person is all about.

There is no more poignant reminder than watching these incredible Olympic athletes to never judge a book by its cover.

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Do Electric Assist Bikes Count As Exercise?

While highly frowned upon when snuck into the Tour de France (are you kidding me?!), electric bikes can be a very useful piece of equipment to zip around town.  These are bicycles that are equipped with electrical assistance, which is activated only when the rider is actively pedalling.  You may wonder – does using these bikes still count as exercise?  A recent study tells us – yes!

The study, published in the European Journal of Applied Physiology, enrolled 20 people who led sedentary lifestyles, and evaluated several measures of health after 4 weeks of using the electrically assisted bike for at least 40 minutes, three days per week. 

They found that using the ‘pedelec’ bikes provided a moderate level of exertion, similar to walking (4.9 METs on average).  After just 4 weeks, there was an improvement in their glucose tolerance, and an increase in their power output and VO2max (a measure of maximal aerobic capacity).    Participants also found the bikes to be fun, to the point where over half of participants ended up cycling over 50% more than the required amount.

So, while using a regular bicycle would provide more exercise, a pedelec bike is a great option for people who have knee problems, struggle to get uphill on a bike, or if you want to get further in a day than you otherwise would on a regular bike.  (We used them on a trip Kyoto last year so we could make it to all the far flung temples we wanted to see – fantastic!)    Pedelecs remove the potential deterrents of cycling such as longer distances or hills, and they can be incorporated into daily life as a means of transport when the weather/climate permits (rather than having to find specific extra time in the day to exercise).  

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Does Exercise Improve Fatty Liver Disease?

Nonalcoholic fatty liver disease is a potential consequence of carrying excess body weight, and is essentially caused by extra fat being stored in the liver. It is the third most common cause of liver cirrhosis, and affects up to 30% of the world’s population. 

Weight loss has been clearly established as the first line treatment for NAFLD, and we know that most successful weight loss strategies focus most attention on reducing calorie intake, with exercise playing only a minor part.  However, we know that exercise can have many cardiometabolic benefits even if a person doesn’t lose weight because of it, so it would be interesting to know if exercise itself could improve NAFLD.

A study was recently published in JAMA Internal Medicine which addresses this question.  In the study, 220 participants with NAFLD were randomly assigned to moderate exercise (brisk walking for 30 mins, 5 days per week) for a year, vigorous exercise for 6 months followed by moderate exercise for 6 months, or no additional exercise for a year.

They found that moderate and vigorous exercise were equally effective to reduce fat content in the liver, and that most (but not all) of the effect was mediated by weight loss. 

So, while actual reduction in weight remains the key factor in improving fatty liver, exercise may play some role even if the exercise itself doesn’t shed a whole bunch of pounds.  And it is good news that moderate activity is just as good as intense activity, as moderate exercise regimens like walking are more likely to be adhered to in the long run.

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The Pokémon Go Revolution - What Public Policy Couldn't Do

We've all seen it: Pokémon Go users are everywhere!  Since it's launch earlier this month, we have seen people everywhere, more enraptured by their smart phones than ever before, playing the game with a joyous enthusiasm.

The engagement in Pokémon Go is paying off in physical activity.  Tracking devices such as Jawbone have seen a major increase in physical activity since the game was launched:

We have never seen any public policy or population based strategy have such an incredible effect on physical activity.  I had a patient in my office this week (who had just found a Pokémon under my examination table) tell me that the game had caused her family's 15 minute walk to turn into a 45 minute adventure where the family enjoyed extra fun time together, and a whole lot more exercise! These stories are abundant on social media.  So cool!

I felt like a massive LED light went on in my brain when I heard about this game - of course!  What a great way to motivate activity, by blending a fun smartphone game with real life exercise.  While this particular game may be a fad, I'm sure that other games are now in hot pursuit to develop the next ones.  I hope that this is the beginning of what may be one of the most successful (and hopefully sustainable) population level 'interventions' to motivate physical activity.

A note to be careful when using this or other games - there have been reports of people falling off of cliffs and standing in freeways playing the game, or playing the game in sensitive places like graveyards - do be careful and mindful when you are enjoying your Pokémon Go adventures.

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www.drsue.ca © 2016

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(In)Accuracy of Your Wrist Technology for Estimating Calorie Burn

There are many different kinds of wrist technology out there - Garmin, FitBit, and Jawbone UP just to name a few.   In response to concerns that these devices may not be accurate to measure energy burn, researchers have now conducted a study to test how accurate they are.


The study, published in JAMA Internal Medicine, examined several brands of wearable energy tracking technology, and compared them to gold standard research methods of measuring energy burn, including both a standardized day (indirect calorimetry using metabolic chamber) and fifteen free living days (doubly labeled water method).  Brands studied included the Garmin VivoFit, Jawbone UP24, and FitBit Flex.

They found that these wearable devices were overall quite inaccurate, with inaccuracies ranging as high as 590 calories per day. !  Most of the inaccuracies were underestimates of caloric needs, while some overestimated needs.

So does this mean that these devices are totally useless?  No.  They can be great motivation for keeping track of daily activity and steps taken per day (pedometer) - though there are inaccuracies here as well.  But I do see a lot of people with weight struggles feeling frustrated that they seem to be burning way more calories (according to their device) than the food they are eating, yet they are not losing weight.   Overall, the biggest benefit of these devices is probably motivation to move, and keeping us engaged in mindful eating (ie we think more about what we are eating if we are keeping track of it).

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New 'Real-World' Obesity Clinical Practice Guidelines

It is an unfortunate fact that despite the high prevalence of overweight and obesity in our society, most health care professionals receive little training in obesity medicine.  I am asked by colleagues just about every day: ‘How do I treat my patient who struggles with excess weight?’  Health care providers often feel lost in this arena.  

There are a number of obesity management guidelines that try to guide the care of people with obesity, but they often do not provide a consensus on a clear and concise approach to management or treatment goals.

Good news! The American Association of Clinical Endocrinologists and American College of Endocrinology have produced a new set of Clinical PracticeGuidelines for obesity that they describe as an evidence based, real-world approach, that gives health care providers practical, straightforward, and tangible algorithms for diagnosis, assessment, and management of people with excess weight.

The theme of these guidelines (which I fully agree with) is that management of obesity is not about the numbers on the scale, but about improving overall health and well being.

The approach to diagnosis and management in these guidelines are nicely packaged into a handful of algorithms and tables that you can access here.  Some of the highlights:

1.  The diagnosis of obesity is not just about the numbers on the scale.  They break down the obesity diagnosis into two components: the anthropometric component (numbers: BMI, waist circumference), and the critically important clinical component (complications of the excess weight, of which they have included a convenient checklist of things to look for and how to screen for them).

2.  There is a beautiful table that lists how much weight loss is recommended to improve any particular complication of obesity (eg 5-15% for type 2 diabetes, 5-15% or more for polycystic ovary syndrome, 7-11% or more for obstructive sleep apnea).

3.  They break down lifestyle treatment into three components: meal plan, physical activity, and behavior modification.  They review pros and cons to different types of diets and where evidence exists for improvement of parameters of health (while emphasizing that the dietary approach needs to be individualized to each patient).

4.  They review pros and cons of medications to treat obesity (note that only two of the medications reviewed are available in Canada – namely, liraglutide and orlistat), along with clinical features that may favor the use of one antiobesity medication over another.

In the spirit of focusing on treating to improve weight-associated health complications rather than focus on numbers on the scale, they suggest more intensive treatment approaches (eg medication or bariatric surgery) in situations where complications of obesity already exist.  Personally, I am inclined to favor a more proactive approach, not only looking at these treatment options to improve upon existing complications of obesity, but also to prevent these complications from developing in the first place.

Overall, these guidelines and nicely packaged tables and algorithms provide a great framework to help health care professionals with a real-world approach to obesity management.  Check it out!

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www.drsue.ca © 2016

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Just How Much (And For How Long) Does Metabolism Slow Down After Weight Loss?

Many people who struggle with excess weight find that they are able to get weight off, but keeping it off seems next to impossible.

So what exactly happens to our metabolism when we lose weight?  And are any changes in our metabolism temporary, or there for the long term?

A very elegant study was conducted that answers this question – and you may be surprised by the results.

The study enrolled people in groups of three, all three of which were of the same gender and weight: one who was weight stable at their maximum lifetime weight (ie had not had any weight loss); one who had lost at least 10% of body weight and kept it off for at least a year; and one who lost at least 10% of body weight over the most recent 5-8 weeks (using a liquid diet for 1-2 months before the study testing was performed).  The average body weight of people in the study was 98 kg (216 lb), and the age range was 19-41 years. All participants lived at the research centre for the duration of the study, and were fed only a liquid formula diet, to ensure their weights were stable for at least 2 weeks before measurements of metabolism were taken.  (a very impressive and dedicated protocol for both participants and investigators, wow!)

They found that in these study participants, the 24h calorie burn was about 450 calories lower for the people who had previously lost weight, regardless of whether that weight loss was just weeks ago, or whether it was years ago (and similar for males and females in the study).  Many full meals come in under 450 calories - I googled this recipe website to give you an idea (though I have not reviewed the recipes per se).  So this means that the person who has lost weight has to eat this much less, EVERY DAY, for years (and possibly forever) in order to maintain that body weight, compared to someone who weighs the same but has never weighed more than that.

Here's an example from that website: it's a lot of food!

While this 450 calorie drop in 24h calorie burn was partly due to a drop in energy burn at rest, the biggest drop was seen in the energy burned by activity (called non-resting energy expenditure). (Read more about all components of daily energy expenditure here). 

So does this mean that people who have lost weight simply exercise less?  No.  Actually, the literature overall suggests that it is energy burn during low-grade activity that declines (ie activities of daily living), because our muscles become more efficient at low levels of physical activity with weight loss. 

So what can you do to combat this reduction in energy burn that happens with weight loss?  Two things.

1.  Be NEAT! NEAT, or non exercise activity thermogenesis, is low grade activity of daily life.  Give up your parking pass and take public transit (which involves more physical activity than driving). If you do drive, park at the far end of the parking lot.  Stand while you talk on the phone.  Take the stairs instead of the elevator.   Read more on NEAT here!

2.  Exercise more.  Easier said than done, and not all may be able to do this because of physical limitations - but it is because of this drop in metabolism that the US Obesity Guidelines recommend more moderate physical activity to prevent weight gain (200-300 mins per week) than they do for weight loss (150 mins per week).  We have only to look at the National Control Weight Registry to see the proof – 90% of Americans who have lost 30 lbs or more, and kept it off for more than a year, exercise for at least an hour each day.

***Be sure to talk to your doctor before starting or ramping up your exercise program, and also to help you find assistance to learn about modified exercises that may work for you if you have physical limitations.***

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www.drsue.ca © 2016

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Caution FitBit HR Wearers - Don't Trust That Your Heart Rate is Accurate!

In the effort to track calorie burn and activity, I have seen many patients coming in wearing a FitBit HR.  So, I decided to get one myself to check it out.

I use a Garmin to track my heart rate during exercise, which requires a sometimes uncomfortable chest strap, so the idea of tracking my heart rate with my neat little FitBit HR wrist band was very appealing indeed.

Unfortunately, what I have found is very disappointing - for me, the FitBit is completely useless to track higher heart rates (and based on online reviews and even lawsuits in the US, I am not the only one).

When I am at rest, my FitBit HR measures my heart rate very well.   Now, watch what happens when I put the pedal to the metal on my spin bike.  Pictured below is my Garmin (white watch, left), measuring my heart rate via the chest strap; on the right is my FitBit HR.

While my actual heart rate was 167, my FitBit HR registered only 108.  

This is beyond shockingly inaccurate and actually quite dangerous - for example, if a person with a heart condition has been advised to keep their heart rate under a certain target, the FitBit HR could dramatically underestimate their actual heart rate and mislead the person to think they are under their maximum target when they are not.

When I drove my output near my max with a heart rate of 180, the FitBitHR didn't register at all, which is safer, as at least it is not misleading the wearer with a wildly incorrect heart rate:

***NOTE: Discuss with your doctor to find out what your appropriate target and/or maximum heart rate should be before embarking on an exercise program. ***

It was only after I had stopped my exercise and my heart rate came down into the 120s that the FitBitHR became accurate again:

 

For those who are wondering if the problem could be the Garmin, it's not - I checked each of these heart rates manually against my own pulse, and the Garmin was accurate (though it too can be inaccurate, for example if you are in a cold environment and/or not sweating).  I have also carried out this experiment with different activities, and yes, I have also tried moving the FitBit HR further up my wrist. The results are the same.

The reason for the inaccuracy comes from the technology used to monitor HR.  While the Garmin strap uses electrical activity from the heart measured via the chest strap, the FitBit HR use optical technology to measure heart rate.  This involves using a LED light to illuminate your capillaries (tiny blood vessels) as blood runs past.  Capillary blood flow isn't as distinctly pulsatile as the bigger blood vessels (arteries), and at higher heart rates, it may be very difficult for this technology to distinguish higher heart rates.    I have not tested any of the other wrist devices using optical technology out there, but I suspect they may be at risk of similar inaccuracies.

What I do like about my FitBit HR is the sleep tracker, and the pedometer (step counter) - though both of these features have their limitations as well.

Thus, please exercise caution in your interpretation of your FitBit HR data - your heart rate, particularly during activity, may be highly inaccurate.

***NOTE: Before starting any moderate or vigorous exercise program, be sure to speak with your doctor.***


Thanks so much to Ryan, Jacqueline, and friends for the fabulous discussion that led to this blog post.

Follow me on twitter! @drsuepedersen

www.drsue.ca © 2016

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#Active365 Goes Public!

Here's a chance to get motivated to stick with those New Year's resolutions you're trying to keep.

Lisa Taylor, a Calgary high school teacher (and, I'm proud to say, my amazing sister), launched a Twitter initiative #active365 to help her phys ed students feel inspired to engage in daily physical activity.  When they get active, they take a picture and post it on Twitter - this gets their classmates hyped about being active, stimulates some friendly competition - and Miss Taylor even gives them bonus marks towards their report card!

We are now taking #active365 outside of gym class and to the general public!  Here's your chance to get friends, family, and work colleagues involved and see who can rack up the most #active365 tweets each week, each month, and for all of 2016.  Being #active365 will mean different things to different people - it can mean walking to work or school instead of taking a bus or car; taking the stairs instead of the elevator; taking your kids for a swim in the local pool; going to the gym; ice skating; starting a new exercise class... use your imagination!  You can choose to tweet with or without a picture, but be sure to describe what you did!

So start racking up those bonus marks to your health - let's tweet up #active365 and motivate each other every day of the year!

I would love to know when my readers are Tweeting at #active365 - my Twitter handle is @drsuepedersen - please add it to your Tweet so I can cheer you on!

Important note: Be sure to discuss with your doctor before starting any new activity or exercise program. 

Follow me on twitter! @drsuepedersen

www.drsue.ca © 2016

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Exercise Prescriptions - How They May Differ In Obesity

In follow up from my recent blog on the Home VO2max text, let's now talk about resting VO2, which is the amount of oxygen we consume at rest per kilogram of body weight per minute, and therefore a measure of basal (resting) metabolism.  This blog post is a little heavy in the math details, but trust me, well worth it to understand for anyone who struggles with their weight, and for any health care professional who cares for people with obesity. Read on!

There are many things that affect resting VO2, including:

• Age (resting VO2 decreases with age)
• lean body mass (resting VO2 is higher with more muscle) 
• higher Body Mass Index (BMI) - resting VO2 decreases with higher BMI.  In other words, people with obesity may have a lower resting VO2, and this gets lower with more excess body weight.  This is due to a number of factors, including genetics, sympathetic nervous system tone, and also because fat tissue is less metabolically active per kg.

The amount of oxygen we consume at rest is equal to one MET (metabolic equivalent) of energy. The amount of oxygen used and energy burned (Calories or kcal) at rest is generally assumed as follows:

Resting VO2 = 1 MET = 3.5 mL/kg/min of oxygen

1 MET = 1 kcal/kg/hour of energy burn

We often describe physical activity in METs:

• Light activity: less than 3 METs
• Moderate activity: 3-6 METs
• Vigorous activity: 6 METs or more

For example: 

• walking at 4 miles per hour is about 3-5 METs (moderate activity)
• shovelling dirt or light snow is 5-7 METs
• jogging at 5mph is about 7-9 METs
• shovelling heavy snow or playing squash is 9 METs or more

A full compendium of METs with particular physical activities can be found here.

Key Point: For some people with obesity, because they may have a lower resting VO2 and therefore a lower resting MET, 'moderate activity' of walking at 4 mph may actually be well into the vigorous METs category for them.

To assign a person with obesity who has a much lower resting VO2 a 'standard' moderate exercise prescription may result in this person feeling heavy exertion at that level of intensity - a potentially unsafe leap in exertional intensity, and also leaving one feeling discouraged that the activity feels too intense to continue.

Therefore, attention health care professionals:  When helping a patient with creation of an exercise prescription, it is important to listen to your patient (as always!), and understand what kind of activity gives them what level of perceived exertion - you may need to start the exercise prescription for your patient with weight struggles at a lower level of activity.   Most exercise prescriptions start with a moderate level of exertion, so for example, if walking at 2mph gives your patient a sense of moderate exertion, this would be where the exercise prescription would start, and you and your patient can build upwards from there.

If you are personally thinking about embarking on an exercise program, be sure to speak with your health care professional to see if any health checks need to be done before you begin.  When you and your health care professional are ready for you to begin, use this awesome METs compendium to find something fun - the choices are endless!

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How Fit Am I? The Home VO2 Max Test

Ever wonder how fit you are, or if this could be measured?  The best measure of aerobic fitness is called the 'VO2max', and is literally equal to the volume of oxygen consumed per minute during maximum exercise effort.

How does VO2max reflect fitness?  Well, we use oxygen to generate energy (called ATP) at rest and during aerobic activity.  Energy can be generated without oxygen for very short periods of time, which is called anaerobic respiration, but the best marker of endurance/cardiorespiratory fitness (which requires oxygen) is the maximum possible oxygen consumption that a particular person can achieve - that is, the VO2max.

The VO2max is most accurately measured in a lab, where oxygen consumption is measured while a person exercises to maximum capacity on a treadmill or stationary bike.

There are a couple of neat ways that VO2max can be predicted: (IMPORTANT: check with your doctor to make sure it's safe for you to do these tests before you proceed)

• the 1 mile walk test
• the 3 minute step test

VO2max ranges and what they mean for fitness level can be found here.

To learn about VO2 at rest, how this translates into METs, how this is important for exercise prescriptions, and how this can be different in people with obesity... stay tuned to www.drsue.ca for more!

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www.drsue.ca © 2015 

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Secrets To Success - Keeping Weight Off

Have you ever wondered what the secret to success might be, for people who have lost weight and have been able to keep it off?

While the answer to this question will be different for each individual, the American National Weight Control Registry was established in 1994 to try to identify behaviors associated with long term weight loss success.   It is the largest prospective observational study of weight maintenance out there, and includes individuals who have maintained a weight loss of at least 30 lbs for at least 1 year.

Some interesting facts about NWCR members:

• 80% are women, 20% men
• average age is 45-50 years
• 45% lost weight on their own, and 55% with a program

Here are the winning patterns of NWCR members:

• 98% modify their food intake in some permanent way: portion control, low fat diet
• 90% exercise at least 1 hour per day, burning at least 400 calories per session
• 78% eat breakfast every day
• 75% weigh themselves once a week
• 62% watch less than 10 hours of TV per week
• average daily calorie intake for women = 1306 cal
• average daily calorie intake for men = 1685 cal

While the causes and contributors to excess weight, and the challenges in maintaining weight loss are different from person to person, it would be worthwhile to consider these permanent habits to improve the likelihood of long term weight management success!

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Keeping Kids Active This Father's Day - And All Year!

In the fight against childhood obesity, it's important to promote an active lifestyle for kids.  Studies show that family based interventions work best to prevent and treat childhood obesity.  Recently, I participated in a fantastic family-oriented triathlon weekend, where kids raced one day and adults the next.  What a great way to get kids interested and enthusiastic in not one but three sports - and adults got to be great role models at the same time!

So this Father's Day weekend, grab your kids and embrace a fun, family-oriented activity - and keep the theme going all year long!

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What Determines Our Daily Energy Burn?

Whether we gain, lose, or maintain weight depends on the balance between calories in, which is what we eat and drink, and calories out, which is the energy that we burn.

So, what exactly determines the calories out side of the equation? 

Our daily calorie burn, also called energy expenditure, is divided into several components: 

1.  Resting Metabolic Rate (RMR)

The RMR is the energy that we use while at, well, rest!  This includes the energy it takes to run our daily functions like breathing, heart pumping, and brain function, and all of the functions of maintenance and repair that go on inside all of our cells on a 24/7 basis.  Believe it or not, this comprises 50-80% of our total daily calorie usage.

The RMR varies greatly from one person to the next, due to differences in lean body mass, age, gender, and genetics.  The RMR is also determined by thyroid hormone levels and the baseline activity of each person's sympathetic nervous system, which produces a baseline level of adrenaline and a tendency towards usage of body fat as an energy source (called lipid oxidation).

2.  Spontaneous Activity

Spontaneous activity refers to everything that we do to move around in a day, from daily living activities to purposeful exercise.  Although one might think this is the biggest part of our daily calorie usage,  it accounts for only 10-25% of our total calorie burn in most people.  

The calorie burn from spontaneous activity varies a lot from person to person, with the biggest variance between individuals actually being due to all of the spontaneous activity excluding purposeful exercise, hence the name non exercise activity thermogenesis or NEAT.  NEAT includes everything from the calories burned during work activities, transport from place to place (eg walking vs driving), and even the amount we fidget!  Interestingly, our tendency for fidgeting behaviors seems to be largely genetically determined.  So, a person who is less inclined to be 'fidgety' will burn less calories in NEAT than a person who is more inclined to be fidgety.    People who have a higher sympathetic nervous system drive tend to have higher NEAT as well. 

The calorie burn from spontaneous activity also depends on body weight, as it requires more calories to carry a higher body weight through life's daily activities.  

3.  Thermic Effect of Food

The thermic effect of food refers to the calories it requires to actually digest the food that we eat, and comprised about 10% of our daily calorie burn.  This can vary somewhat, depending on the types of food eaten (protein requires more calories to digest than carbs or fat), and by sympathetic nervous system activity.  However, the jury is still out as to whether differences in the thermic effect of food plays a role in obesity or not.  

So, a few tips to take away in terms of weight management: 

• With weight loss, the daily calorie burn in resting metabolism and spontaneous activity actually decreases, because there is less weight to maintain and carry around in a day. (Think of a 20 lb weight loss like taking off a 20lb backpack - less weight to carry around means lower calorie burn).  Our metabolism actually slows when we lose weight as well, further decreasing the calories that we need to eat.  So, the 'calories in' side of the equation needs to be scaled back as a person is losing weight, to stay in tune with the decreased calories burned with weight loss. 
• Think about being NEAT!  In other words, try to put more movement in your day.  Rather than being still after dinner, go for a walk instead.  Take the stairs instead of the elevator.  Look for a further parking spot instead of a closer one. 
• Use an exercise program to burn calories, but also to gain muscle mass (as a higher muscle mass increases your RMR). 

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