Tuesday, March 25, 2014

Mothers Who Limit TV Time Have Slimmer Kids

            How much time kids spend with entertainment media is strongly linked to weight. More TV time generally means higher body weight. Many research studies have consistently shown this over the years. The possible reasons are many. More television watching may mean less physical activity. Watching television while eating may be related to “mindless eating” and eating more calories. Food advertising during children’s programs is aggressive and effective and the ads push sweet, high calorie foods like candy and sodas.
            However, can parents influence, for the better, the effects of media on their kids?  A new study shows that the answer may be “yes”. Researchers followed 112 mothers and 103 fathers of 213 children. They interviewed the children and their parents at ages five, seven, and nine and gave them physicals at each of those ages. They found that the children of mothers who did not monitor their entertainment viewing tended to be heavier at age seven than at age five. They also found that weight in general was more irregular over the whole study period with less motherly media monitoring. Fathers’ media monitoring did not have any influence on their children’s weights. The effects of the mothers’ monitoring were independent of the parents’ BMI, education, and income. So that means the media monitoring itself was related to lower body weight!
            This is an important study because it shows that parents may be able to influence their children’s weight by actively monitoring and restricting how much time they spend watching TV and playing video games. There may be other good reasons to limit your children’s media use. Studies show that too much media may also be linked to attention problems, eating and sleep disorders, and, of course, obesity. Too much media can have such a negative impact on our children’s health that the American Academy of Pediatrics actually has guidelines for how much media kids should be using.
The American Academy of Pediatrics Media & Children Guidelines:

  • All entertainment media should be avoided for infants and children under 2 years old
  • Have a “screen free zone” meaning no entertainment media in children’s bedrooms or during dinner

  • Limit Children & Teens to 2 Hours or Less of High Quality Entertainment Media 

  • Encourage Children to Play Outside, Read, and Play Games
  • Set an Example By Limiting Your Own Media Time

       This study has its limitations. This kind of study cannot show cause and effect but there did seem to be a link between mothers’ media monitoring and their kids’ body weights. The study was done in Oregon and most of the children were Caucasian so we don’t know if these results apply other ethnic areas or geographic locations. Parents reported on their own behaviors and how much TV their children watched so they may not have provided completely accurate information. 

Beth Kitchin, PhD, RDN
Assistant Professor, Nutrition Sciences
University of Alabama at Birmingham

American Academy of Pediatrics. www.aap.org. accessed 3/24/14.

Tiberio SS, Kerr DCR, Capaldi DM, Pears KC, Kim HK, & Nowicka PN. 2014. Parental monitoring of children’s media consumption: the long-term influences on body mass index in children. JAMA Pediatrics online.

Friday, March 7, 2014

These Old Bones Aren’t as Old as You Think!

            Dolly Parton sings “These old bones will tell your story, these old bones will never lie”. But your bones only tell part of your story because every 10 years, you have a completely new skeleton. This is a little known “factoid” that I love relaying to my patients in the UAB Osteoporosis Prevention and Treatment Clinic because it’s really kind of cool.
                We think of our bones as being with us throughout our lives but your bones are in a constant state of flux. Cells called “osteoclasts” break down old bone and make way for cells called “osteoblasts” to come along and build new bone in its place. The rate of this “bone remodeling” ends up replacing much of our adult bones from the previous ten years! So if you’re 45, your skeleton is not really made up of any of the same bone you had at 35.
                This bone remodeling also paves the way for bone loss and possibly osteoporosis later in life because as we get older the osteoclasts speed up and the osteoblasts slow down. In other words, we are losing more bone than we can replace. For women, this is a particular problem as our estrogen levels drop with menopause. Estrogen slows down the osteoclasts (the cells that break down old bone) so when we lose estrogen we lose bone much more quickly. Getting older also speeds up bone loss in both men and women.

For more information about osteoporosis visit our virtual clinic at www.uab.edu/toneyourbones

Beth Kitchin, PhD, RDN
Assistant Professor, Nutrition Sciences
Patient Educator, UAB Osteoporosis Prevention & Treatment Center
University of Alabama at Birmingham

Thursday, October 3, 2013

Exercise: The Best Medicine

A very interesting article was just published in the British Medical Journal. The researchers reviewed meta-analysis studies that compared exercise and medications to each other or placebo and the effects they had on the risk of death. Collectively, these studies suggest that exercise and medications have similar outcomes when it comes to lowering death. 

A quick lesson about Meta-Analyses:  Any time you see an article that talks about results of a meta-analysis, you should proceed with caution!  A meta-analysis is tricky business. Researchers combine data from several studies and reanalyze it as one study. They do this when there are few large, definitive studies in a specific research area. So they take a bunch of studies that meet their specific criteria as far as study design, research variables, study participant characteristics, etc. and crunch the data together. This method is imperfect at best because no matter how similar studies may be, the differences in how the data were gathered can result in much less precise results when you put all the data together. That said, these studies can be useful in areas where larger studies are lacking.  And if the researchers conducting the meta-analyses use rigorous methods, then the data can at least be somewhat useful. 

What this study found: The results of this particular meta-analyses are particular interesting and encouraging. The researchers looked at studies that looked at deaths related to heart disease, stroke, heart failure, and pre-diabetes. The risk of all of these diseases can be lowered by diet and exercise. But no one has ever shown if exercise by itself can reduce the risk of dying from these diseases or if exercise is as effective as medicines in lowering the risk of dying from these diseases. 
For heart disease and prediabetes, the researchers found that exercise was just as effective as medicines for preventing deaths caused by these two common diseases. In the case of stroke, exercise was found to be more effective than medicines in preventing death from stroke. 

What kind of exercise? Because the studies reviewed were meta-analyses, the exercise programs in each of the studies were different. Most used a combination of muscle strengthening exercises and aerobic exercise like walking, biking, or swimming.
The exciting message – that we do have to approach with caution – exercise may be as effective – and in some cases more effective – than medicines when it comes to treating several  of the diseases that Americans are most likely to die from. Since medicines can be expensive and have possible side effects, this is a good news message. And don’t forget that exercise has other benefits as well such as improving mood and your ability to do the day to day activities you need and want to do.

Beth Kitchin, PhD, RDN
Assistant Professor,Nutrition Sciences
University of Alabama at Birmingham

Naci, H. & Ioannidis, J. Comparative effectiveness of exercise and drug interventions on mortality outcomes: metaepidemiological study. 2013. BMJ 347:f5577.