Does Obesity Begin In Kindergarten?

Written by Dr. Steve Chaney on . Posted in Issues, Obesity

Is Obesity Caused By Bad Genes Or Bad Lifestyle?

 Author: Dr. Stephen Chaney

 In past issues of “Health Tips From the Professor” I have shared some common sense weight loss tips. But what if it is all for naught? What if there is nothing you can do about your weight?

Fat ChildYou may have seen the headlines suggesting that obesity in kindergarten is a very strong predictor of obesity later in life. If so, you are probably wondering what that means for your kids or grandkids – and what it means for you. You are probably asking questions like:

  • Should you be worrying about that your toddler’s baby fat?
  • What can you do as parents and grandparents to protect the ones you love from a lifetime of obesity and all of the health challenges that involves?
  • Is there anything you can do about overweight and obesity? Are some people just fated to be obese from childhood on?

What Does the Study Actually Show?

This was a very well done study. It followed 7738 children of all socioeconomic classes who were enrolled in kindergarten (mean age 5.6) in the US in 1998 and followed them through the 8th grade (mean age 14.1) (Cunningham et al, New England Journal of Medicine, 370: 403-411, 2014).

When the children entered kindergarten, 12.4% of them were obese, and another 14.9% of them were overweight. By the time they reached the 8th grade 20.8% were obese and 17% were overweight. Those results didn’t make the headlines. They are similar to many previous studies.

The results that made the headlines were:

  • Overweight 5 year olds were 4 times more likely to become obese by age 14 than normal weight 5 year olds.
  • 87% of obese 8th graders (14 year olds) had a body mass index above the 50th percentile in kindergarten, and 75% had a body mass index above the 70th percentile.
  • Only 13% of overweight 8th graders had been normal weight (<50th percentile) in kindergarten, and only 13% of the normal weight 8th graders had been overweight in kindergarten.

These results are fully consistent with earlier studies showing that overweight toddlers are likely to become overweight teens, and overweight teens are likely to become overweight adults. What was unique about this study (and generated the headlines) was the precision of the statistics.

Does Obesity Begin In Kindergarten?

The answer to that question is clearly yes. However, the more important question is what message we, as responsible health advocates, should be sharing with the general public. Let me break that down to some of the most important questions that you are probably asking.

Is Obesity Caused By Bad Genes Or Bad Lifestyle?

Bad GenesTaken on face value, the results of this study might seem to suggest that genetics is the primary cause of obesity. However, if that is the message we convey to the public, it is likely to simply fuel the perception that most overweight individuals are genetically destined to be obese. There is nothing they can do about it. So, why even bother trying?

However, the authors of the study also noted that the percentage of children aged 6 to 11 who are above the 95% percentile of weight has increased 4-fold between 1963 and 2000. Genetics does not change in a mere 37 years (37 generations maybe). That 4-fold increase in severe childhood obesity is clearly driven by lifestyle changes over the past 30 or 40 years.

While nobody knows the exact percentages, a reasonable interpretation of recent research in this area might be:

  • 10-15% of us are genetically destined to be obese. There is little we can do to change our weight, but a healthy lifestyle can significantly reduce our risk of disease.
  • 10-15% of us are genetically predestined to be lean no matter what we eat (Yes. Your suspicions are true). Once again, lifestyle has relatively little influence on our weight, but a healthy lifestyle can significantly reduce our risk of disease.
  • The other 70-80% of us are genetically predisposed to become obese if we adapt the typical American lifestyle. For most of us lifestyle choices can make a big difference in our weight as well as our health.

So the answer to this question is BOTH. For most of us, obesity is caused by bad genes AND bad lifestyle.

When Should We Intervene?

You probably already know that any extra fat cells we develop in childhood never go away. They are always with us, looking for those extra calories they can store as fat.

This study suggests that by the time we are in kindergarten, the die may already be cast. Those extra fat cells may have already developed.

And, for many people, the time to intervene may be even sooner. This study also showed that birth weight plays an important role as well. Children who weighed 9 pounds or more at birth were 2-fold more likely to be obese in kindergarten than children who weighed less than 9 pounds at birth.

Once again, a small percentage of overweight babies is due to genetics, but it is lifestyle choices during pregnancy that lead to the majority of overweight babies.

The authors of the study noted that most public health initiatives (school lunch programs, lifestyle education programs, etc.) are targeted at school aged children. The authors went on to say that by then it may be too late to have any significant effect on the incidence of obesity in our children.

They suggested that we need to place a stronger emphasis on influencing lifestyle changes that affect the weight of babies at birth and are likely to influence whether or not they become obese by the time they reach kindergarten.

That’s not the realm of public health policy. That’s our responsibility.

What Should We Do?

If You Are Pregnant:

  • The old adage “You are eating for two” was never true.
  • Aim for an extra 150 calories during the 1st trimester, 300 during the 2nd and 3rd trimesters (That’s 1 or 2 servings of healthy foods).
  • Aim for little or no weight gain during the 1st trimester and a total of 20-26 pounds during the last two trimesters (a bit less if you are overweight).

If You Have a Young Child Who Is Overweight:

  • Don’t restrict calories. Restricting calories can stunt growth and interfere with normal mental and physical development.
  • Encourage your kids to exercise rather than watching TV and playing video games. You may need to set the example, and that’s a good thing for you as well as for them.
  • Provide your kids with a healthy diet. For most kids, that means more fruits and vegetables and less sugary beverages, fruit juices, and processed snack foods. That may simply mean that you don’t bring those kinds of foods into your house. Again, that would probably be a good thing for everyone in the family.

I know some of you are saying “My kids won’t eat healthy stuff”. Let me give you my take on that.

When I was a kid, my mom had a pretty simple policy. If I didn’t like what she cooked, I didn’t have to eat it. I could simply wait until the next meal – when she would be serving the same kinds of healthy foods again.

I got the message pretty quick. It wasn’t eat healthy or eat junk food. It was eat healthy or go hungry. I decided early on that healthy was better than hungry.

Now, let me step down from my soapbox and summarize.

The Bottom Line:

1)     The latest research suggests that if a child is overweight by kindergarten, they are likely to be overweight for the rest of their lives. So if you want to spare your kids and grandkids  from a lifetime of obesity, you want to intervene early.

2)     A small percentage of those kids are destined to be obese no matter what they do. However, for the vast majority of them obesity can be prevented by a healthy lifestyle.

3)     If you are pregnant, don’t “eat for two”. That is terrible advice. If your pre-pregnancy weight is stable (neither increasing or decreasing), you only need to add a serving or two of healthy foods to your diet during pregnancy. Check with your doctor about the amount of weight gain that is right for you and follow their advice.

4)     If you have a young child who appears to be overweight, don’t restrict their calories. Instead, provide them with healthy food choices and encourage them to exercise.

5)     Finally, if you have been overweight since childhood, don’t despair. For most of us obesity is a combination of genetic predisposition and lifestyle choices. You can’t your genes, but you can change your lifestyle.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

Tags: , , , ,

Trackback from your site.

Comments (1)

  • Darlene T. Ewers

    |

    I have four adult sons, who were born in 1969, 1972, 1977, and 1979, and none of them are obese or overweight due to poor diets. I enforced the rules outlined in the above article, by providing my sons with healthy snacks upon arrival home from school. They were then sent out to play outdoors until supper time. The rule was that they didn’t have to eat what I cooked, but they had to eat what they took. If they didn’t eat, they couldn’t substitute junk food for my meals.

    The first son is a physician’s assistant, the second is a licensed practical nurse, the third is a music teacher, and the fourth is a career Army officer. I’d say I did well by my children, teaching them the proper way to eat and enjoy good health for years to come!

    Reply

Leave a comment

Recent Videos From Dr. Steve Chaney

READ THE ARTICLE
READ THE ARTICLE

Latest Article

A Low Carb Diet and Weight Loss

Posted January 15, 2019 by Dr. Steve Chaney

Do Low-Carb Diets Help Maintain Weight Loss?

Author: Dr. Stephen Chaney

 

low carb dietTraditional diets have been based on counting calories, but are all calories equal? Low-carb enthusiasts have long claimed that diets high in sugar and refined carbs cause obesity. Their hypothesis is based on the fact that high blood sugar levels cause a spike in insulin levels, and insulin promotes fat storage.

The problem is that there has been scant evidence to support that hypothesis. In fact, a recent meta-analysis of 32 published clinical studies (KD Hall and J Guo, Gastroenterology, 152: 1718-1727, 2017 ) concluded that low-fat diets resulted in a higher metabolic rate and greater fat loss than isocaloric low-carbohydrate diets.

However, low-carb enthusiasts persisted. They argued that the studies included in the meta-analysis were too short to adequately measure the metabolic effects of a low-carb diet. Recently, a study has been published in the British Medical Journal (CB Ebbeling et al, BMJ 2018, 363:k4583 ) that appears to vindicate their position.

Are low carb diets best for long term weight loss?

Low-carb enthusiasts claim the study conclusively shows that low-carb diets are best for losing weight and for keeping it off once you have lost it. They are saying that it is time to shift away from counting calories and from promoting low-fat diets and focus on low-carb diets instead if we wish to solve the obesity epidemic. In this article I will focus on three issues:

  • How good was the study?
  • What were its limitations?
  • Are the claims justified?

 

How Was The Study Designed?

low carb diet studyThe investigators started with 234 overweight adults (30% male, 78% white, average age 40, BMI 32) recruited from the campus of Framingham State University in Massachusetts. All participants were put on a diet that restricted calories to 60% of estimated needs for 10 weeks. The diet consisted of 45% of calories from carbohydrate, 30% from fat, and 25% from protein. [So much for the claim that the study showed low-carb diets were more effective for weight loss. The diet used for the weight loss portion of the diet was not low-carb.]

During the initial phase of the study 161 of the participants achieved 10% weight loss. These participants were randomly divided into 3 groups for the weight maintenance phase of the study.

  • The diet composition of the high-carb group was 60% carbohydrate, 20% fat, and 20% protein.
  • The diet composition of the moderate-carb group was 40% carbohydrate, 40% fat, and 20% protein.
  • The diet composition of the low-carb group was 20% carbohydrate, 60% fat, and 20% protein.

Other important characteristics of the study were:

  • The weight maintenance portion of the study lasted 5 months – much longer than any previous study.
  • All meals were designed by dietitians and prepared by a commercial food service. The meals were either served in a cafeteria or packaged to be taken home by the participants.
  • The caloric content of the meals was individually adjusted on a weekly basis so that weight was kept within a ± 4-pound range during the 5-month maintenance phase.
  • Sugar, saturated fat, and sodium were limited and kept relatively constant among the 3 diets.

120 participants made it through the 5-month maintenance phase.

 

Do Low-Carb Diets Help Maintain Weight Loss?

low carb diet maintain weight lossThe results were striking:

  • The low-carb group burned an additional 278 calories/day compared to the high-carb group and 131 calories/day more than the moderate-carbohydrate group.
  • These differences were even higher for those individuals with higher insulin secretion at the beginning of the maintenance phase of the study.
  • These differences lead the authors to hypothesize that low-carb diets might be more effective for weight maintenance than other diets.

 

What Are The Pros And Cons Of This Study?

low carb diet pros and consThis was a very well-done study. In fact, it is the most ambitious and well-controlled study of its kind. However, like any other clinical study, it has its limitations. It also needs to be repeated.

The pros of the study are obvious. It was a long study and the dietary intake of the participants was tightly controlled.

As for cons, here are the three limitations of the study listed by the authors:

#1: Potential Measurement Error: This section of the paper was a highly technical consideration of the method used to measure energy expenditure. Suffice it to say that the method they used to measure calories burned per day may overestimate calories burned in the low-carb group. That, of course, would invalidate the major findings of the study. It is unlikely, but it is why the study needs to be repeated using a different measure of energy expenditure.

#2: Compliance: Although the participants were provided with all their meals, there was no way of being sure they ate them. There was also no way of knowing whether they may have eaten other foods in addition to the food they were provided. Again, this is unlikely, but cannot be eliminated from consideration.

#3: Generalizability: This is simply an acknowledgement that the greatest strength of this study is also its greatest weakness. The authors acknowledged that their study was conducted in such a tightly controlled manner it is difficult to translate their findings to the real world. For example:

  • Sugar and saturated fat were restricted and were at very similar levels in all 3 diets. In the real world, people consuming a high-carb diet are likely to consume more sugar than people in the other diet groups. Similarly, people consuming the low-carb diet are likely to consume more saturated fat than people in the other diet groups.
  • Weight was kept constant in the weight maintenance phase by constantly adjusting caloric intake. Unfortunately, this seldom happens in the real world. Most people gain weight once they go off their diet – and this is just as true with low-carb diets as with other diets.
  • The participants had access to dietitian-designed prepared meals 3 times a day for 5 months. This almost never happens in the real world. The authors said “…these results [their data] must be reconciled with the long-term weight loss trials relying on nutrition education and behavioral counseling that find only a small advantage for low carbohydrate compared with low fat diets according to several recent meta-analyses.” [I would add that in the real world, people do not even have access to nutritional education and behavioral modification.]

 

low carb diet and youWhat Does This Study Mean For You?

  • This study shows that under very tightly controlled conditions (dietitian-prepared meals, sugar and saturated fat limited to healthy levels, calories continually adjusted so that weight remains constant) a low-carb diet burns more calories per day than a moderate-carb or high-carb diet. These findings show that it is theoretically possible to increase your metabolic weight and successfully maintain a healthy weight on a low-carb diet. These are the headlines you probably saw. However, a careful reading of the study provides a much more nuanced viewpoint. For example, the fact that the study conditions were so tightly controlled makes it difficult to translate these findings to the real world.
  • In fact, the authors of the study acknowledged that multiple clinical studies show this almost never happens in the real world. These studies show that most people regain the weight they have lost on low-carb diets. More importantly, the rate of weight regain is virtually identical on low-carb and low-fat diets. Consequently, the authors of the current study concluded “…translation [of their results to the real world] requires exploration in future mechanistic oriented research.” Simply put, the authors are saying that more research is needed to provide a mechanistic explanation for this discrepancy before one can make recommendations that are relevant to weight loss and weight maintenance in the real world.
  • The authors also discussed the results of their study in light of a recent, well-designed 12-month study (CD Gardener et al, JAMA, 319: 667-669, 2018 ) that showed no difference in weight change between a healthy low-fat versus a healthy low-carbohydrate diet. That study also reported that the results were unaffected by insulin secretion at baseline. The authors of the current study noted that “…[in the previous study] participants were instructed to minimize or eliminate refined grains and added sugars and maximize intake of vegetables. Probably for this reason, the reported glycemic load [effect of the diet on blood sugar levels] of the low-fat diet was very low…and similar to [the low-carb diet].” In short, the authors of the current study were acknowledging that diets which focus on healthy, plant-based carbohydrates and eliminate sugar, refined grains, and processed foods may be as effective as low-carb diets for helping maintain a healthy weight.
  • This would also be consistent with previous studies showing that primarily plant-based, low-carb diets are more effective at maintaining a healthy weight and better health outcomes long-term than the typical American version of the low-fat diet, which is high in sugar and refined grains. In contrast, meat-based, low-carb diets are no more effective than the American version of the low-fat diet at preventing weight gain and poor health outcomes. I have covered these studies in detail in my book “Slaying The Food Myths.”

Consequently, the lead author of the most recent study has said: “The findings [of this study] do not impugn whole fruits, beans and other unprocessed carbohydrates. Rather, the study suggests that reducing foods with added sugar, flour, and other refined carbohydrates could help people maintain weight loss….” This is something we all can agree on, but strangely this is not reflected in the headlines you may have seen in the media.

The Bottom Line

 

  • A recent study compared the calories burned per day on a low-carb, moderate-carb, and high-carb diet. The study concluded that the low-carb diet burned significantly more calories per day than the other two diets and might be suitable for long-term weight control. If confirmed by subsequent studies, this would be the first real evidence that low-carb diets are superior for maintaining a healthy weight.
  • However, the study has some major limitations. For example, it used a methodology that may overestimate the benefits of a low-carb diet, and it was performed under tightly controlled conditions that can never be duplicated in the real world. As acknowledged by the authors, this study is also contradicted by multiple previous studies. Further studies will be required to confirm the results of this study and show how it can be applied in the real world.
  • In addition, the kind of carbohydrate in the diet is every bit as important as the amount of carbohydrate. The authors acknowledge that the differences seen in their study apply mainly to carbohydrates from sugar, refined grains, and processed foods. They advocate diets with low glycemic load (small effects on blood sugar and insulin levels) and acknowledge this can also be achieved by incorporating low-glycemic load, plant-based carbohydrates into your diet. This is something we all can agree on, but strangely this is not reflected in the headlines you may have seen in the media.
  • Finally, clinical studies report averages, but none of us are average. When you examine the data from the current study, it is evident that some participants burned more calories per hour on the high-carb diet than other participants did on the low carb diet. That reinforces the observation that some people lose weight more effectively on low-carb diets while others lose weight more effectively on low-fat diets. If you are someone who does better on a low-carb diet, the best available evidence suggests you will have better long-term health outcomes on a primarily plant-based, low-carb diet such as the low-carb version of the Mediterranean diet.

For more details read the article above.

 

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

UA-43257393-1