New Study Confirms Breastfeeding Not Protective for Childhood Obesity

March 14th, 2013 1 comment »

A new study published in JAMA concludes that breastfeeding is unlikely to prevent the development of obesity in children up to 11 ½ years old. The study, involving 17, 046 breastfeeding mother-infant pairs,  contributes to the conclusion reached in an earlier posting, Breastfeeding and Obesity.

Note to Mayor Bloomberg: It’s Harder than you think

September 27th, 2012 No comments »

On September 13, 2012, the New York City Board of Health enacted Mayor Michael Bloomberg’s proposal to limit the size of cups selling soda in New York City. The soda cup size ban over 16 oz only for facilities subject to inspection: restaurants, movie theatres, and stadium concession stands. Not covered are convenience stands, including 7-Elelven’s  (and its king-size Big Gulp drinks), vending machines and some newsstands. Also not affected are fruit juices, dairy-based  drinks like milkshakes or alcoholic beverages and non-caloric beverages. Fast food restaurants with self-service drink fountains would not be allowed to stock cups larger than 16 ounces. http://www.nytimes.com/2012/09/14/nyregion/health-board-approves-bloombergs-soda-ban.html.

There is no ban on  buying  two under 16oz cups of soda, selling ‘two for the price of one’, or free re-fills.

While most anti-obesity advocates shudder at the thought of sugar sweetened beverages, there is doubt over whether a ban on the size of the cup in which they are delivered is going to have much impact. Here’s why.

  1. Most sugar sweetened beverages (SSBs) are consumed by teenage boys, especially low income African-American and Hispanic. The ban rests on a hope that the consumers will voluntary switch from SSBs to some non- or low-caloric beverage. Yet, there is no educational campaign or subsidy to get them to substitute an SSB for another no/low-calorie drink. http://www.cdc.gov/nchs/data/databriefs/db71.pdf
  2. Males consume an average of 178 kcal from ssbs on any given day. Among males 12-19, consumption is highest at 273 kcal a day. This is still only a small  fraction of their total daily caloric intake. http://www.cdc.gov/nchs/data/databriefs/db71.pdf

At 273 kcal a day, a person would put on about 28 pounds a year. This is not happening, so the caloric intake is probably balanced to a large, if not full extent, by energy expenditure. The CARDIA study of 18-30 African-American and white men  and women   found that physical fitness changes were most strongly associated with weight changes over 7 years. Weight changes in this study range from 5.2kg in white women to 8.5 in African-American women.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1380845/pdf/amjph00503-0109.pdf

  1. Over half of sugar drink kilocalories, 52%, are consumed in the home, 92% having been purchased in stores. Presumably, the store-bought items are in cans and bottles, not in the cup sizes subject to the NYC ban. Of the 48% of kcal consumed away from home, 35.5% are purchased in fast-food restaurants and 1.4% in schools or daycare settings. 20% are consumed in vending machines, cafeterias, street vendors and community food programs. So, only about 1/3 of sugar drink consumption is in restaurants or fast-food outlets.   http://www.cdc.gov/nchs/data/databriefs/db71.pdf
  1. SSBs, while associated with increased daily caloric intake, are not the leading source. According to Harvard researchers Frank Hu and colleagues, the components most associated with increased intake are potato chips (1.69 lbs), potatoes (1.28 lbs), SSBs, (1 lb) unprocessed red meats (0.95 lb) and processed meats (0.93 lb), in that order. http://www.ncbi.nlm.nih.gov/pubmed/21696306.
  1. African-Americans need many changes to diet to affect CVD risk factors, including additional whole grains, vegetables and fish intake, reduction in saturated fat, sodium as well as sugar according to study by Carson et al in September 2012 Journal of the Academy of Nutrition and Dietetics. PubMed: Cardiovascular Health of Urban African Americans (I think this applies to all of us.)
  1. The most influential factor driving childhood obesity is parental weight, especially that of the mother, independent of the effect of socio-economic status. See Causes of Obesity also, http://www.ncbi.nlm.nih.gov/pubmed/19165162 A new study from Elmear Keane and  colleagues in Ireland provides further support for this. PubMed: Measured weight status and familial SES

To look at the combination of genetic pre-disposition to obesity and in the intake of SSBs, Qibin Qi  and colleagues at Harvard School of Public Health looked  at 32 genetic loci (called “risk alleles”) known to be associated with BMI.  They grouped the 32 loci into 3 groups and looked at prospective 4 year beverage intake data from two large studies. Participants who were obese at baseline were excluded.  They found a rising BMI from greater intake of SSBs. For every 10 risk alleles, the increases for BMI was 1.0 for one serving a month, 1.2 for one to four servings per week, and 1.85 for one or more servings per day. In a sub-analysis,  they excluded the FTO gene, known for its impact on body weight, and found similar results. They concluded that “persons with a greater genetic predisposition to obesity appeared to be more susceptible to the deleterious effects of sugar –sweetened beverages on BMI. PubMed: Sugar-Sweetened beverages and Genetic Risk of Obesity The implication of this article is that NYC may have overreached…applying a rule to all when only some are most affected.

Two intervention studies were published in the New England Journal of Medicine, along with the study above.  One, by Cara Ebbeling and colleagues, divided 224 overweight and obese adolescents into 2 groups. The first group received home delivery of non-caloric beverages and were followed for another year. The second group acted as controls. Consumption of SSBs in the first group declined significantly but at the end of 2 years there was not difference in BMI between the two groups.PubMed: Randomized Trial of SSB and Adolescent Weight

The other intervention study, by de Ruyter and colleagues, had a larger sample size (641 normal weight children from 4 yrs 10 months to 11 yrs 11 months) and was a double blind model.  Half received a sugar-free non-carbonated beverage and the other have a sugared non-carbonated drink.  26% dropped out of the study. If this were an obesity drug study, a great deal would be made of this. Evidently they dropped out because they no longer liked the taste of the beverage. The researchers assume they went back to consuming sugared beverages. They found that “masked” replacement of the SSB by a sugar-free beverage significantly reduced weight gain and fat accumulation in normal weight children. The difference was 1.01kg. However, the authors calculate that approximately 0.8kg of the differences in weight gain was due to fat mas and associated muscle and other tissues.  PubMed: Trial of sugar-free or sugar-sweetened beverages

You can listen to David Allison discuss the SSB issue and these studies at http://themixuab.blogspot.com/2012/09/do-sugar-sweetened-drinks-drive-obesity.html.

These studies were published in the New England Journal of Medicine September 21, 2012 edition.  Mayor Bloomberg could have looked at other recently published studies to see the difficulty of regulating consumption of SSBs.

Levy et al looked at school nutrition policies and price interventions directed at youth consumption of sugar sweetened beverages (SSBs). They found that school nutrition and price policies reduce SSB consumption and that reduced SSB consumption is associated with a reduction in energy intake that “can” influence Body Mass Index Their review of the literature found that the effects of nutrition policies on BMI were less conclusive, possibly due to the lack of adequate follow-up period or that reduced SSB consumption in school is compensated for by increased SSB consumption outside of schools. The authors’ concluded that, “The reduction in energy intake from even just one 8-oz serving of SSB appears enough to have important effects on the prevalence of overweight and obese youth if policies are started at early ages and maintained.”  PubMed: Review of the literature on policies youth consumption of SSB

Of course, the key word here is “if.” Some of the calculations of the benefits of reducing or eliminating SSBs, are premised on the assumption that the calories contained in SSB will not be compensated for by other caloric intake. PubMed: Effect of school district policy change on consumption of sugar An analysis of SSB consumption in middle schools compared students in states which reduced access and purchase with those that did not. The main finding was that SSB consumption was not associated with state policy, i.e. in-school access is reduced but overall consumption is not changed. PubMed: Banning all sugar-sweetened beverages in middle schools A study by Wang et al, calculated what a penny-per-ounce tax on SSBs would mean for health care costs and diabetes. They calculated that 40% of the calories in SSB would be replaced by other caloric intake and 60% of SSB calories would not be replaced. This would translate to a mean reduction of 0.9 pound in mean at the population level, with a greater impact on younger adults, a 1.5% reduction in the number of adults with obesity. This decline would further translate into a reduction of new cases of diabetes by 2.6% and cost savings over ten years of $17.1 billion. PubMed: Penny-per-ounce tax on sugar-sweetened beverages. However, the 40%-60% split was only an estimate, it wasn’t based on experimental or real world results.

News reports indicate 24 states and 5 localities which proposed taxes on sugar sweetened beverages failed in their attempts over the past 2 years. Industry resistance to taxes and regulation has been strong and effective. ( Reuters: Special Report: How Washington went soft on childhood obesity http://www.reuters.com/article/2012/04/27/us-usa-foodlobby-idUSBRE83Q0ED20120427, accessed April 28, 2012)

Worldwide, some 20 countries have banned all sugar-sweetened beverages from schools and about 12 have banned 100% fruit juice as well, according to Barry Popkin and colleagues. PubMed: Global Nutrition Transiiton and the Pandemic of  Obesity Hawkes and colleagues have found that 26 countries have made explicit statements on food marketing to children and 20 or so are developing explicit policies in the form of statutory guidelines or approved forms of self-regulation. PubMed: Regulationg the commercial promotion of food to children

Denmark last year became the first nation to tax sugar but has since rescinded its tax because it was hurting domestic businesses while Romania has introduced a lower value-added-tax on staple foods. New Zealand is researching taxing foods with little or no nutritional value at higher rates than more nutritious foods. Professor Sir Nicholas Wald, director of the Wolfson Institute of Preventive Medicine has proposed an all-embracing SASS (salt, sugar, alcohol and saturated fat) tax.  PubMed: Is a tax on junk food moving closer?

One alternative approach is to tax all SSB sales, whether in school or out of school. Researchers have pointed out that, in 2007, 34 states taxed soda sold in grocery stores and 39 taxed soda sold in vending machines at mean rates of 3.4% and 4.0% respectively. The tax was never greater than 10% of the price.  Several studies are cited which showed no effect on BMI from such taxes. PubMed: A review of the literature directed at the youth consumption of SSB Sturm et al point out the greater benefit of larger tax than a smaller tax to affect behavior. PubMed: Soda taxes, soft drink consumption, and children’s body mass index.

For an excellent discussion of food taxes, see these presentations from University College, Dublin.

The New York City experiment will be tested in court and then it will be tested in practice to see if it actually has an effect on reducing weight gain or causing weight loss. But there are other public policy options worth exploring. Mayor Bloomberg also proposed a waiver for the city from the Department of Agriculture to allow restrictions on the purchase of certain foods by families with SNAP benefits. SNAP is the Supplemental Nutrition Program for Women, Infants and Children. SNAP is a federal program designed to reduce hunger and food insecurity among low-income Americans.  In a study using store scanner data, Tatiana Andreyeva and colleagues at the Rudd Center for Food Policy and Obesity  looked at patterns in the New England states. They found on average that SNAP households purchased 689 oz of beverages per month, including 399 oz or 58% of SSBs. The researchers estimated that SNAP spends annually between $1.713 billion to $2.05 billion on SSBs. They note that no-calorie beverages and water were equally available and no more expensive. SNAP households appear to obtain more total energy from SSBs than the general, higher-income population. PubMed: Grocery Store Beverage Choices by Participants in Federal food

So there are other public policy options. But this debate over SSBs show the problem with over-simplifying obesity to one source, fashioning a simplistic response, only to see the “solutions” fail. This stuff is difficult and we need to appreciate how difficult it truly is.

 

Time for a reappraisal

September 14th, 2012 No comments »

I have a blog on the STOP Obesity Alliance website on the latest research on the effectiveness of public policy interventions to prevent obesity.

See:  http://www.stopobesityalliance.org/blog/time-for-a-reappraisal-of-public-policy-interventions-on-obesity

 

 

USAToday Coverage of IOM Recommendations

May 8th, 2012 1 comment »

Multiple strategies needed to fight obesity, study suggests

By Nanci Hellmich, USA TODAY

Updated 1h 12m ago

WASHINGTON – Taming the obesity epidemic in this country needs an all-hands-on-deck strategy so that schools provide students 60 minutes of physical activity daily, fast-food restaurants offer healthier fare for kids, and communities build recreational spaces that encourage physical activity, says a new report out Tuesday. 

  • A new report recommends kids have 60 minutes of active time per day.By Reed Saxon, APA new report recommends kids have 60 minutes of active time per day.

By Reed Saxon, AP

A new report recommends kids have 60 minutes of active time per day.

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It’s going to take “bold actions” like these and a full-scale effort across all segments of society to reduce the obesity epidemic, says the report from experts convened by theInstitute of Medicine, which provides independent advice on health issues to policy makers, foundations and others.

The goals and some of the strategies were presented here at the Centers for Disease Control and Prevention’s “Weight of the Nation” meeting, where experts are discussing ideas for the prevention and control of obesity.

Currently, two-thirds of adults and a third of children in the USA are overweight or obese, government statistics show. Another study out Monday predicted that as many as 42% of adults may be obese, roughly 30 or more pounds over a healthy weight, by 2030 if actions aren’t taken to reverse the trend.

Extra weight takes a huge toll on health increasing the risk of type 2 diabetes, heart disease, stroke, many types of cancer, sleep apnea and other debilitating and chronic illnesses, and it costs billions of dollars in extra medical expenditures.

The Institute of Medicine committee reviewed more than 800 obesity prevention recommendations to pinpoint the most effective ones.

The report says there is no one answer to this problem, but it’s going to require bringing all the pieces together — the schools, the workplace, health care providers, says Dan Glickman, chairman of the institute committee and former secretary of the U.S. Department of Agriculture. “There are no magic bullets in here, but this report puts it all together.”

The illnesses and costs associated with obesity are spiraling out of control, he says. “If we don’t address this comprehensively, it will basically take us down as a society.”

M. R. C. Greenwood, vice chairwoman of the committee and president of the University of Hawaiisystem, says, “Many people will probably say ‘what’s new’ and what’s new is the clear statement that we must begin to attack this problem collectively on all fronts. It’s a massive problem unlike anything we have ever tackled before.”

Here are the five goals and a some strategies suggested for achieving them:

Make it easier for people to work physical activity into their daily lives. For instance, people need to have safe places to be active including trails, parks, playgrounds and community recreation centers.

Create an environment where healthy food and beverage options are the routine, easy choice.

Fast-food and chain restaurants could revise menus to make sure at least half of their kids’ meals comply with government’s dietary guidelines for moderately active 4- to 8-year-olds, and that those meals are moderately priced.

Businesses, governments and others should adopt policies to reduce the consumption of sugar-sweetened beverages including making clean water available in public places, work sites and recreation areas.

Improve messages about physical activity and nutrition.

The food, beverage, restaurant and media industries should take voluntary action to adopt nutritionally based standards for marketing aimed at children and adolescents, ages 2-17. If those standards aren’t adopted within two years by the majority of companies, then local, state and federal policymakers should consider setting mandatory nutritional standards for marketing to this age group.

Expand the role of health care providers, insurers and employers in obesity prevention.

Employers should provide access to healthy foods at work and offer opportunities for physical activity as part of their wellness/health promotion programs.

All health care providers should adopt standards of practice for preventing, screening, diagnosing and treating people who are overweight or obese.

Make schools a national focal point for obesity prevention.

Students should have nutrition education throughout their school years, and kids in kindergarten through 12th grade should have the chance to engage in a total of 60 minutes of physical activity each school day. This should include participation in quality physical education.

“There’s so much to do, and the country is still doing so little,” says Margo Wootan, director of nutrition policy for the Center for Science in the Public Interest, a Washington-based consumer group. “It seems heartless that we’re abandoning two-thirds of the American population to obesity-related diseases.”

There are lots of ways for students to get an hour of physical activity during the school day including recess, PE, walking and biking to school, classroom activities and after-school sports, Wootan says. “Kids need a chance to run around in order to sit still and learn in the classroom.”

When it comes to food marketing to kids, “companies claim to be taking meaningful action, but still the overwhelming majority of food ads aimed at kids are for unhealthy foods,” she says.

“What industry says is healthy to market to kids is not what most parents and health professionals think is healthy.”

Not everyone is convinced that the actions outlined in the report will make a dent in the obesity problem. “The literature in evaluating interventions like these shows weak effectiveness at best,” says Morgan Downey, editor and publisher of the downeyobesityreport.com. “So rather than evaluate the strategies’ effectiveness, they (the committee members) are just shouting them even louder.”

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Posted 11h 11m ago | Updated 1h 12m ago

 

Weight of the Nation: Childhood Obesity – Is Anything Working?

May 4th, 2012 No comments »

The Surgeon’s General ground-breaking Call to Action on overweight and obesity came out in 2001. Surgeon General: Call to Action: Obesity Since then, millions of dollars have been spent by governmental and non-governmental organizations on steps to prevent obesity, primarily in children. How’s it going? Well, in spite of the best of intentions of hundreds of people, not well.

A paper just out by Dr. Jeffrey Mechanick , a highly respected researcher in the field, and colleagues, looked at three anti-obesity policies: increasing physical activity in children, taxing sugar-sweetened beverages and funding for walking and biking trails. They found, “While numerous studies have established their efficacy when implemented on a local or communal (small-) scale, there is little published evidence demonstrating statistical correlation between BMI (body mass index) and implementation of these policies, or any combination, thereof, on a statewide (large-) scale.” They conclude, “American culture, policy-making, and the obesity epidemic constitute a recursive, complex adaptive system. We have proposed that an emergent property of this system is that implementation of anti-obesity policies may not be reducing the obesity growth rates as early as expected, if at all. This somewhat counter-intuitive finding is, on the surface, discouraging, but with deeper deliberation, offers redirection for an anti-obesity campaign. Since the obesity epidemic remains uncontrolled with vast downstream adverse effects, it is imperative to gain a thorough understanding of this complex system. The focus should be broadened to improve consumer dietary patterns and physical activity. There should be greater supply-side regulation of food content, as well as interventions targeting obesogenic inflammatory mechanisms. PubMed:Lack of Correlation between anti-obesity poliicy and obesity growth rates

This one paper is not alone. The Cochrane Reviews are distinguished for their rigorous study of important health topics. A Cochrane Review was published in 2011 evaluating all randomized clinical trials (RCTs) of interventions for preventing obesity in children. The review included an 55 studies. The majority of studies targeted children aged 6-12 years. The meta-analysis included 27,946 children. According to the authors, overall, the programs were effective, but not all were, reflecting a high degree of heterogeneity. Children in the intervention group had a standard mean difference in adiposity  (measured as BMI or zBMI) of –0.15 kg/m2 The authors urged that the findings be taken cautiously because of the unexplained heterogeneity and the likelihood that studies with negative outcomes were not published. Cochrane Review: Preventing Obesity in Children

A near-universal policy goal is increasing physical activity of children in school. Yet, even here, the evidence is poor to weak.

Cawley and colleagues examined the impact of state physical activity requirements on youth physical activity and overweight, using data from the Youth Risk Behavior Surveillance System for 1991, 2001, and 2003. They found that high school students with a binding physical education (PE) requirement report an average of 31 additional minutes per week spent physically active in PE classes. Their results indicate that additional PE time raises the number of days per week that girls having exercised vigorously or have engaged in strength-building activity. They found “no evidence” that PE lowers BMI or the probability that a student is overweight. They conclude that “there is not yet the scientific basis to declare raising PE requirements an anti-obesity initiative for either boys or girls. PubMed: Cawley: The Impact of state physical education requirements

A 2011 paper found that adequate PE time was inversely related to recess, and vice versa, suggesting that schools are substituting one form of physical activity for another, rather than providing the recommended amount of both recess and PE.  PubMed: Slater: The Impact of State Laws and District Policies

 

Competitive Food Sales in Schools Not Affect Obesity

February 2nd, 2012 No comments »

Most US middle and high schools sell soft drinks, candy and chips to their students. These practices have been widely criticized as contributing to childhood and adolescent obesity. However, a new study followed  approximately 19,450 children from fifth to eight grade. Researchers found the children’s weight gain was not associated with the introduction or the duration of exposure to competitive foods. This did not vary by gender, race/ethnicity or family socioeconomic status. Possible explanations are that children’s food preferences and dietary patterns are firmly established before adolescence. Also, schools are highly structured whereas home life may have more opportunities for snacking. http://www.asanet.org/images/journals/docs/pdf/soe/Jan12SOEFeature.pdf.

NIH Disses Physical Activity as Cure of Childhood Obesity

November 23rd, 2011 No comments »

The National Heart, Lung and Blood Institute has issued guidelines endorsed by the American Academy of Pediatrics. They are directed to all primary pediatric care providers to address the known risk factors of cardiovascular disease, including obesity, blood pressure, cholesterol, tobacco and lipids.

The report notes that longitudinal data on non-white populations are lacking and that “Clinically important differences in prevalence of risk factors exist according to race and gender, particularly with regard to tobacco-use rates, obesity prevalence, hypertension, and dyslipidemia.”

The report notes, “Obesity tracks more strongly than any other risk factor, among many reports from studies that have demonstrated this fact…Tracking data on physical data is more limited.”

Regarding overweight and obesity, the report states,

“The dramatic increases in childhood overweight and obesity in the United States since 1980 are an important public health focus. Despite efforts over the last decade to prevent and control obesity, recent reports from the National Health and Nutrition Examination Survey show sustained high prevalence: 17% of children and adolescents have a BMI at the >95th percentile for age and gender. The presence of obesity in childhood in childhood and adolescence is associated with increased evidence of atherosclerosis at autopsy and of subclinical measures of atherosclerosis on vascular imaging. Because of its strong association with many of the other established risk factors for cardiovascular disease, obesity is even more powerfully correlated with atherosclerosis; this association has been shown for BP, dyslipidemia, and insulin resistance in each of the major pediatric epidemiologic studies. Of all of the risk factors, obesity tracks most strongly from childhood into adult life.”

Given that physical activity is a primary prescription for preventing childhood and adolescent obesity, it is interesting to read what the expert panel has to say about its utility:

“A moderate number of RCTs (randomized controlled clinical trials) have evaluated the effect of interventions that addressed only physical activity and/or sedentary behavior on prevention of overweight and obesity. In a small number of these studies, the intervention was effective. It should be noted that these successful interventions often addressed reduction in sedentary behavior rather than attempts to increase physical activity. In a majority of these studies there was no significant difference in body-size measures. Sample sizes were often small and follow-up was often short (frequently < 6 months). ..Overall, the expert panel concluded that on the basis of the evidence review, increasing activity in isolation is of little benefit in preventing obesity. By contrast, the review suggests that reducing sedentary behavior might be beneficial in preventing the development of obesity.”

The report identifies populations at special risk for obesity: children with a BMI between the 85 and 95th percentiles;children in whom there is a positive family history of obesity in 1 or both parents; early onset of increasing weight; excessive weight gain during adolescence; children who have been very active and become inactive. See Integrated Guidelines for Cardiovascular Health and Risk Reduction in Children and Adolescents- NHLBI, NIH

AHRQ Looking at Comparative Effectiveness for Prevention Wt. Gain in Adults

September 5th, 2011 No comments »

The Agency for Healthcare Research and Quality is undertaking a comparative effectiveness review of approaches to weight maintenance in adults. Information is available at Approaches to Weight Maintenance in Adults: A Comparative Effectiveness Review | AHRQ Effective Health Care Program The paper cites a recent Cochrane review of workplace diet and physical activity which found a rather minimal decrease in weight of 2.8 pounds or .5 BMI unit at 6-12 months.