Sunday, December 29, 2013

Putting Diets to the Test

As a new year begins, it will be hard to avoid diet propaganda. I call it propaganda because in my review of the weight loss literature, I find very little evidence that diets are effective for the majority of people who try them. [In contrast, adopting a certain diet pattern (e.g., Mediterranean or plant based) as a life style is health promoting.] 

In some ways, diets are like medication and this may explain why diets fail.  First, like hypertension medication, diets work as long as you ‘take’ them and few diets are palatable or tolerable enough to 'take' forever. Second, like medication for serious mental illnesses, the side effects may be so harsh that the people who need the medicine most cannot tolerate it; like a diet which causes an excess amount of flatulence.  Third, the medication regimen may feel more tedious than the immediate or future disease complications seems to warrant; like drinking vinegar after every meal. Lastly, like pain medications, diets may need tweaking in order to remain effective; once weight is lost, a person requires fewer calories to maintain the new weight.  

Diets are not medications however; they are behavioral modifications or interventions. Considering the above analogies, a successful behavioral intervention for weight loss is as much dependent on the person as it is the intervention. To be successful, the intervention/diet needs to be one that a person is able to follow (with occasional adjustment) without mental or physical anguish for their entire life.  A person could not return to unrestrained eating or reduce their level of physical activity and expect the benefit of said diet to continue.  

Another important factor regarding diets is the amount of weight loss necessary for an individual or sponsor (e.g., government, worksite, researcher) to consider the diet ‘successful.’ Scholars Tomiyama, Ahlstrom and Mann recently raised this issue in an article they wrote for the journal Frontiers in Psychology.  In their article, they suggest holding behavioral interventions, including diets, to the same standards of evidential effect as medications (i.e., FDA approval).  Recall that a drug company has to proceed through certain steps when requesting a new drug application.  It has to show a drug:

  • is safe, usually done first in animal studies 
  • has limited side effects (ones that are outweighed by the benefit of the medicine)
  • addresses an issue or disease that significantly impairs health or quality of life
  •  is better than an existing drug for this particular disease 
    •  the new drug has to be more effective, have less severe side effects or both  
    •  or the regimen for the new drug has to be easier to tolerate than the current treatment (e.g., a once a month injection for osteoporosis treatment vs a daily or weekly pill taken on an empty stomach) 

Drug companies usually start a drug application with the intention of treating only one disease, but they must identify the disease.  Testing goes from the lab, to small groups, to large clinical trials, and then to post market evaluation. 

Imagine the same process for a diet intervention and include efficacy and effectiveness markers, as Tomiyama and colleagues suggest.  A diet intervention (or drug) is efficacious when it works in a lab under controlled conditions and effective when it works in the real world under less than ideal situations –where people might not follow every instruction, every time.  This is where diets seem to fail the most.

Tomiyama and colleagues give a thorough commentary on using FDA standards to test behavioral interventions and they use obesity as their example.  I was able to access the full article after clicking this link and then the tab on the right that says ‘provisional pdf.’ If this idea (testing interventions with the same rigor as testing new medications) intrigues you, I strongly recommend you read the original article.  

My last thought regards something the authors did not mention in comparison to drug trials, but which I would add – marketing and labeling.  A drug company can only market a drug to treat the condition tested in clinical trials.  In addition, marketing material and product labels must include information on side effects; instruct people how to take the drug, and state that not everyone will have the same benefit or side effects when using it.  I would be happy to see this sort of disclosure with diet programs, and expect that if such a high standard were required, most diets would fail to reach ‘market.’

Instead of trying a diet program or worse, diet supplement you see advertised in the coming weeks, why not read more about a health promoting pattern of eating from Harvard’s Nutrition Source – here.

Tomiyama A, Ahlstrom B and Mann T (2013). Evaluating eating behavior treatments by FDA standards. Front. Psychol. 4:1009. doi: 10.3389/fpsyg.2013.01009

Monday, December 16, 2013

Using Advertising to Improve Diet

The post for today was written, by me, as an exercise for a class I am taking to improve my writing.  I chose the study for blog relevance and personal interest, but it may seem more formal than my usual, opinion- infused posts.  Now you know why :)

 In the United States, obesity rates have risen over the past 40 years (Ogden & Carroll, 2010), and many health professionals consider the disease to be epidemic.  The suggested causes of obesity are numerous, interconnected and multi-level.  Because individual level prevention programs are expensive and generally ineffective, researchers have begun testing environmental or societal level strategies that can affect whole populations (Swinburn, Egger, & Raza, 1999).  For example, Rusmevichientong, Streletskaya, Amatyakul and Kaiser (2014) recently conducted a laboratory experiment to compare the effect of 4 types of food advertising on lunch purchases.  The researchers expected that limiting unhealthy food advertising, increasing healthy food advertising and airing anti-obesity messages would each lead to the purchase of items with less calories, fat, sugar and sodium.

If advertisement manipulation is effective in reducing over consumption in the short term, public health advocates will have evidence to promote advertising interventions or policies, which may lead to a reduction in obesity rates over the long term.  Rusmevichientong and colleagues offer some evidence in this regard.

 Rusmevichientong and colleagues randomly assigned 182 adult college students into one of 4 treatment conditions.  All participants watched TV for about 16 minutes. In all but one group (the control), the participants viewed four, five or six, 30 to 60 second advertisements in one of the following categories: unhealthy food advertisements (unhealthy foods were defined as items high in sugar, fat and sodium), healthy food advertisements (ones promoting the consumption of fruits and vegetables), anti-obesity messages, and a mixture of all three types. Before and after the TV viewing, each participant chose a lunch meal from a computerized menu.  The researchers provided $10 meal vouchers, but participants had to pay the difference if their order was more than $10.  The researchers compared the food orders before and after the TV viewing (within participants) and the changes between the groups, including the control. The research design (different in difference) allowed the researchers to compare the magnitude of difference between ad types.

In this laboratory experiment; exposure to the healthy food messages, anti-obesity messages and a mixture of unhealthy, healthy, and anti-obesity messages, led to an increase in healthy food purchases and a decrease in number of calories purchased. The healthy food messages produced the greatest decrease in calories purchased (134) compared to anti-obesity messages (93) or mixed messages (90). There was also some reduction in the fat and sodium content in the meals purchased.  In addition, Rusmevichientong and colleagues found a positive association between these 3 advertisement conditions and ‘becoming healthier,’ which they defined as purchasing a greater number of healthy foods at time 2.  The researchers suggest using anti-obesity ads judiciously and thoughtfully (i.e., ones that are not stigmatizing or fear producing) and healthy food advertising to reduce the over consumption of calories in the US adult population.
Rusmevichientong and colleagues results are important because most research suggesting a relationship between both anti-obesity messages and reduced caloric consumption, and healthy food ads and reduced caloric consumption is based on cross sectional surveys.  Experimental studies allow researchers to claim causal inference, e.g., healthy food ads change behavior. However, this particular study was small, took place outside of a natural setting and used a homogenous set of participants.  Policy advocates may present this evidence along with evidence produced from representative, field based, cross-sectional or longitudinal studies to make a case for new advertising polices.

Ogden, C. L., & Carroll, M. D. (2010). Prevalence of overweight, obesity, and extreme obesity among adults: United States, trends 1960–1962 through 2007–2008. NCHS Health and Stats.
Rusmevichientong, P., Streletskaya, N. A., Amatyakul, W., & Kaiser, H. M. (2014). The impact of food advertisements on changing eating behaviors: An experimental study. Food Policy, 44(0), 59-67. doi:
Swinburn, B., Egger, G., & Raza, F. (1999). Dissecting obesogenic environments: The development and application of a framework for identifying and prioritizing environmental interventions for obesity. Preventive Medicine, 29(6), 563 - 570. doi: 10.1006/pmed.1999.0585


Wednesday, December 11, 2013

Will you really burn off those extra calories?

In a recent Nutrition Notes Daily, published by the American Society for Nutrition, a professor from UCLA School of Medicine was quoted as saying, "it takes a lot of exercise to make up for a little dietary indiscretion."  
A vast body of research supports his assertion. Even so, many of us believe that an extra 30 minute walk will erase the damage of a 500 calorie donut, piece of cake or holiday cookies.  It is not so.  In this past post, I introduced the MET or metabolic equivalent as one way to determine how many calories you might burn doing a certain activity at a certain intensity for a certain amount of time.  For example, I found that I burned less than 500 calories by running at a ten minute per mile pace for just over an hour.
In a more recent post, I talked about the belief we have in the self control of our future self.  For example, the belief that tomorrow you will walk twice as long as usual in order to burn off the extra calories you ate today.  Often tomorrow comes and well, its today, so there you are... pinning your hopes on the next tomorrow. 
This is especially important from Thanksgiving to New Years.  One or two days of indulgence can be self corrected, four to six weeks of eating more calories than you need, will lead to weight gain and extra weight is hard to lose. 
(And when you start seeing weight loss ads in January remember that the only way to lose weight or to maintain a weight that is healthy for you, is to make a change that you can stick with - forever.  A short term plan will get you a short term fix and whatever trick you try will only work as long as you use it.)

Sunday, December 8, 2013

Does Cancer Change the Dialogue?

Scientists have found that certain genes may place people at risk for disease (e.g., cancer, Alzheimers), but that having the gene does not in and of itself always cause the disease. Epigenetics is the study of how a gene gets turned on, or is 'expressed'.  The expression of a gene is due to some interaction between biology and environment.  In other words, a person may have a gene that puts them at risk for a certain type of cancer but the gene stays dormant or asleep until some other "thing" or "series of things" occurs.  There is ongoing research into the epigenetics of diet and cancer.  In other words, does the diet of a person turn on a cancer gene? 

As a researcher, I am interested in how diet (what and how much a person eats) affects health.  Because some research suggests that a diet high in calories, sugar and certain types of fat leads to obesity, heart disease and diabetes, I feel that it is appropriate to use law to help us limit our consumption of certain foods or food ingredients.  This is a very contentious idea.  Americans' believe that food choices are personal (I believe food choices are swayed by industry, the environment, and social norms).  Some people also believe that being overweight or having heart disease is an acceptable outcome for the enjoyment food provides.  Within that person's value system, the risk of heart disease is not considered high or important.

I wonder if this same global mentality will accompany a finding that too many calories or a diet high in sugar turns on a cancer gene.  People still fear cancer.  Cancer (though seemingly as treatable as heart disease) is not usually considered an acceptable outcome for food indulgences in anyone's value system.

I expect that laws limiting fast food restaurants, taxing sugar sweetened beverages and mandating interpretive, nutrient disclosures (i.e., traffic light labels) will get more support if researchers find a link between the over consumption of certain foods and cancer.

My desire is to test the effect of such laws or strategies, regardless of why they are implemented.  To learn more about my 'new' research interests please click here for my professional website.

Tuesday, December 3, 2013

Labeling Rules ~ The FDA has us all in limbo

Any day now, or more likely, sometime in 2014, the FDA will release the final rule for the national nutrition/menu labeling law officially meant to apply to restaurants (sit down and counter chains), vending companies, and similar retail establishments.

As of today, the consumer (you and I),  health advocates (myself,  CSPI, the RUDD Center,  many others), the National Restaurant Association, the National Grocers Association, the Association for Convenience and Fuel Retailing, pizza restaurants and other food selling/entertainment venues (e.g., bowling alleys, cinemas) remain unawares and unprepared for what will be required.

Of those listed above, the consumer interest groups (and thus a majority of the general public), public health folks and the National Restaurant Association supported the menu labeling law, but the others did not nor did they expect to get caught up in it.  My personal belief is that anyone selling ready to eat, unpackaged food has an obligation to share with the buyer of that food, pertinent nutrition information.  I would include food sold from steam tables in grocery stores, hot dogs and the like sold in convenience stores and items sold from concession stands at bowling alleys, sports arenas and movie theaters.

I do think that pizza joints should get some leeway in how they present the information due to the individual, made to order nature of pizza.

Once the FDA makes its announcement, retailers will have 6 mos to 1 year to comply.  Then the next battle begins.  Updating the nutrition facts panels on packaged foods. In this case, the concern 
(of food companies) is whether the update is going to mandate  labels that imply a foods goodness, e.g., star ratings or multiple traffic lights.