Do Low Fat Diets Prolong Life?

There is hot debate these days as to whether low fat diets are good or bad for us, and whether we have gone overboard in promoting low fat as the way to go in guidelines over the last several decades.

A recent study, published in the British Medical Journal, conducted a systematic review and meta analysis, with their goal actually being to determine whether dietary lifestyle interventions targeting weight loss reduces mortality, cardiovascular disease, and cancer in people with obesity.  They hadn't intended to study low fat diets in particular, but out of the 54 randomized clinical trials that they identified for analysis, all but one of these trials described a low fat diet being included as at least one of their interventions (and all but three trials included some form of exercise advice).  The diets were also usually low in saturated fat.

In this analysis of over 30,000 clinical trial participants in studies of at least 1 year duration, they found that weight loss interventions decreased mortality by 18%, corresponding to 6 fewer deaths per 1000 participants in the studies.  Weight loss after 1 year was 3.4kg (7.5lb), and about 2.5kg (5.5lb) after 2-3 years.

That this study found that dietary interventions reduce mortality in people with obesity is noteworthy, as the amount of weight lost was fairly low, and also because singular diet studies have not shown a reduction in mortality.  In fact, the only obesity studies that have really shown a reduction in mortality are those of bariatric surgery.  It is encouraging that perhaps a mortality benefit from lifestyle intervention emerges when we look at enough people together (as in the current study).

But does this mean that low fat diets are the way to go?   Not necessarily.

It is true that we cannot know if the benefits seen in this study were because of the weight lost, because of the low fat nature of the diets, or a combination of both.

However, a problem with the low fat diet approach in real life (ie outside of a clinical trial) is that it most often results in overconsumption of carbohydrates, which has likely contributed to the increase in obesity that we have seen in the last several decades.  The Mediterranean diet, which is not a low fat diet (fat intake is 35-47% of total calories, with a focus on the healthier unsaturated fats), has been shown to be associated with a reduction in mortality (in systematic reviews and meta analyses of cohort and case control studies). 

We must also remember that all systematic reviews and meta analyses of studies are subject to limitations in interpretation as they are compiling data from a variety of different studies, so they must all be taken with a grain of salt.

BOTTOM LINE: This study suggests that weight reducing diets (which happened to be mostly low fat diets) may reduce mortality.  I would now like to see more studies of diets with moderate carbohydrate restriction and more generous unsaturated fat intake to understand if these diets may have the same benefit.

Follow me on twitter! @drsuepedersen

www.drsue.ca © 2017

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Does Earlier Menopause Mean A Higher Risk Of Diabetes?

Menopause is a major life transition for women, both psychologically and physiologically.  A number of changes occur in a woman's body that alters metabolism, unfortunately tipping the scales towards an increase in cardiovascular risk.  We know that an earlier age of menopause increases the risk of cardiovascular disease, and that a later age of menopause onset seems to be protective.

Whether earlier age of menopause increases the risk of developing type 2 diabetes has been somewhat controversial; a new study sheds additional light on this question.

The study, published in the journal Diabetologia, evaluated 3639 postmenopausal women from the population based Rotterdam study.  They followed these women for a median of 9.2 years, with the goal of assessing how the risk of developing type 2 diabetes may vary depending on the age of menopause.

They found that the risk for developing type 2 diabetes, compared to women with late menopause (at more than 55 years old), is:

• 3.7 times higher for women with premature menopause (at less than 40 years old)
• 2.4 times higher for women with early menopause (at 40-44 years old)
• 1.6 times higher for women with normal age of menopause (at 45-55 years old)

They found that for every year later that menopause occurred, the risk of developing diabetes decreased by 4%.

So why would the risk of diabetes go up with earlier menopause? With menopause comes a natural decrease in our reproductive hormones (estrogen, progesterone, and testosterone).   These changes promote a loss of muscle and an increase in fat, especially the visceral fat that sits around our abdomen and internal organs - this is the fat that has negative effects on our metabolism.  A loss of progesterone, and hot flashes from having lower estrogen levels, can impair sleep, which is a known risk factor for obesity and metabolic syndrome.  The emotional challenges of menopause may bring out an increase in emotional eating for some women, which can promote weight gain and increase diabetes risk as well.

Interestingly, this study looked at several reproductive hormone levels at the start of the study, and showed that earlier menopause was associated with an increase risk of diabetes, independent of these hormone levels, and also independent of body mass index at baseline or shared genetic factors.

The authors hypothesize that earlier menopause and type 2 diabetes may be a consequence of epigenetic changes, which are changes that alter the physical structure of our DNA.  Epigenetic changes can be caused by a number of factors, including poor diet, smoking, and many other environmental factors. 

Further studies need to be done looking at epigentic changes to determine if these may be responsible for the association between earlier menopause and diabetes risk. If epigentic changes are at play here, living well and healthily throughout life is more important than ever!

After menopause, we can combat cardiovascular and diabetes risk by:

• Keeping active - engage those muscles! This helps to combat the decrease in muscle mass. 
• Making healthy permanent lifestyle changes 
• Having good sleep hygiene
• Getting help from your doctor if you are struggling with menopausal symptoms.

Follow me on twitter! @drsuepedersen

www.drsue.ca © 2017

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Time To Take ACTION! Barriers To Effective Obesity Care

Despite the fact that obesity is one of the most prominent medical conditions in existence, it is sadly one of the most poorly treated. There exists very little education about obesity for health care providers, and the stigma against obesity is even stronger in the medical community than it is in the general population. Although this is slowly changing, only a small minority of people with obesity actually have this medical condition addressed and treated with the help of their health care provider.

The ACTION study was thus designed to better understand the barriers to effective obesity care. This study was a survey conducted in USA, completed by three groups of people:

• 3,008 people with obesity
• 606 health care providers (primary care/family medicine, internal medicine, and obesity specialists)
• 153 employers who provide health insurance or wellness programs to their employees

Here are some of the key findings: 

1.  While over 80% of health care providers viewed obesity as a chronic disease, only 55% of people with obesity reported receiving an actual diagnosis of obesity. (How can a health care provider move towards treatment of this medical condition if they are not making the diagnosis?)

2. Top 5 reasons that health care providers reported as to why they may not initiate a conversation about weight loss: 

• not enough time
• more important issues to discuss
• they did not believe their patient was motivated to lose weight 
• they did not believe their patient was interested in losing weight (au contraire - data supports that the vast majority of people with obesity are interested in losing weight)
• concern over patient's emotional state or psychological issues

3.  Top 5 barriers to initiating a weight loss effort (agreed to be the same top 5 by people with obesity, health care providers, and employers):

• lack of exercise (note: exercise is less important for weight loss and more important for weight maintenance)
• lack of motivation (could this be because of a lack of understanding of the causes and contributors to each individual's weight struggle?)
• preference for unhealthy food (could this be because food is being used to medicate untreated depression or pain by releasing 'happy hormones' in our brains?)
• controlling hunger
• cost of healthy food

4. Only 24% of people who had a discussion about obesity with their doctor had a follow up appointment scheduled. (Obesity requires long term management - one appointment isn't enough!)

5. Only 17% of people with obesity felt that their employers' wellness offerings were helpful in weight management.


The ACTION study is truly a treasure trove of information that should help all components of  society better identify, understand, and gradually overcome the barriers to successful weight management.

You may be wondering if the results of the ACTION study applies to Canada or other countries, as attitudes and approaches can be very different in different parts of the world.  I'm thrilled to share that the ACTION study is currently underway in Canada (I am on the steering committee for this study) - stay tuned for our results next year. ACTION will be conducted in several countries around the world as well, with deployment planned to begin in 2018.

Disclaimer: The ACTION study is funded by Novo Nordisk, the maker of weight management medication Saxenda (liraglutide 3.0mg).

Follow me on twitter! @drsuepedersen

www.drsue.ca © 2017

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