Skim Milk May Not Lower Obesity Risk Among Children

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Got milk? It turns out that low-fat versions may not be the answer to helping kids maintain a healthy weight. Long a staple of childhood nutrition, milk is a good source of calcium and vitamin D, which can help to build bone, and experts believed that lower-fat versions could help children to avoid the extra calories that came with the fat in whole milk.

But in a study published in the Archives of Disease in Childhood, scientists found that skim and low-fat milks may not be as useful for weight loss as experts had hoped.

Since 2005, both the American Academy of Pediatrics (AAP) and the American Heart Association (AHA) recommended that children drink skim or low-fat milk after age two. Because whole milk has more calories from fat than skim, 1% fat or 2% fat versions, the thinking was that the lighter varieties would help youngsters to avoid weight gain and curb the growing problem of overweight and obesity in childhood.

Not all of the studies supported this idea, however; some found no relationship between the type of milk preschoolers drank and their body weight, while others found that skim milk drinkers were heavier than their whole milk-drinking counterparts. So Dr. Mark Daniel DeBoer, an associate professor of pediatric endocrinology at the University of Virginia School of Medicine and his colleagues turned to a large database of 10,700 children in the Early Childhood Longitudinal Survey, Birth Cohort to investigate the relationship between the type of milk children drank and their body mass index (BMI).

The survey tracked the long term health of a population of American kids born in 2001, and the researchers interviewed the caregivers and parents of the kids when they were two and again when they were four about what kind of milk the kids drank: skim, 1% semi-skimmed milk, 2% milk, full fat milk or soy. When the children were four years old, the scientists also asked the parents about how often the children consumed other beverages, including fruit juices, sports drink and sugared sodas.

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The findings surprised DeBoer and his team. Overweight or obesity rates were relatively high among the children at both ages; 30% of the two years olds and 32% of the four year olds had BMIs that qualified them as overweight or obese. But it wasn’t the normal weight children who were drinking the most skim or 1% fat milk. In fact, after adjusting for the effect of the other beverages, 14% of the heavier two year olds drank 1% milk compared to 9% of normal weight youngsters, and 16% of the overweight or obese four year olds drank the 2% milk compared to 13% of the normal weight four year olds. Overall, children who drank the 2% milk showed lower BMI scores than those drinking the 1% milk.

Even more puzzling, when DeBoer analyzed how choice of milk might be affecting weight over time, he found that children who were normal weight at the start of the study and consistently drank the 1% milk, showed a 57% increased chance of becoming overweight or obese by the they were four.

“Our original hypothesis was that children who drank high-fat milk, either whole milk or 2% would be heavier because they were consuming more saturated fat calories. We were really surprised when we looked at the data and it was very clear that within every ethnicity and every socioeconomic strata, that it was actually the opposite, that children who drank skim milk and 1% were heavier than those who drank 2% and whole,” says DeBoer, who is also the chair-elect for the AAP Committee on Nutrition.

DeBoer says when they broke down the data into the different types of milk with increasing fat content, the findings were even more striking. As BMI scores went up among the kids, the amount of fat in the milk they were drinking went down. “So the ones drinking skim were by far the heaviest, and those drinking whole milk were the lightest,” he says.

(MORE: Predicting Obesity at Birth)

One explanation for the results might be that parents of heavier children may be more likely to switch their youngsters to 1% of skim milk in an effort to lower the amount of calories they drink. But the data on normal weight two year olds who drank 1% milk and still gained weight contradicts this idea. “In that sense it was a little deflating that skim milk and 1% milk didn’t restrain the amount of weight gain in the groups over time,” says DeBoer.

It’s also possible that the skim milk drinkers were more likely to consume more calories overall; DeBoer and his colleagues were not able to incorporate data on other foods that the children ate. The study also did not account for genetic factors and family history of obesity. “I think it’s an interesting paper, but not necessarily conclusive,” says Dr. Linda Van Horn, a nutritional spokesperson for AHA and a Professor of Preventive Medicine for the Northwestern University Comprehensive Center on Obesity. “It is important to remember that this study was not directly observed. It was 100% dependent on parental reports, and that gets harder as the kids get older. When they are away at daycare and grandmas, you just don’t know what they eating.”

Dr. Stephen Daniels, the chairman of the department of pediatrics at the University of Colorado, agrees. “We do not know enough about the rest of their diet or their activity levels,” says Dr. Stephen Daniels the chairman of the department of pediatrics at the University of Colorado. “So, one possibility is that the kids on skim would be on an even steeper rise for weight had they been on whole milk. The investigators point out that the rate of gain between the two groups between ages 2 and 4 were not significantly different, making it less likely that skim milk was a cause of increased weight gain.”

The fact that whole milk drinkers may still end up weighing less than skim milk drinkers despite the added calories from fat actually does make some sense, however. It’s possible, for example, that the fat in whole milk may help kids to feel more full, and therefore eat fewer calories in a day than those who drink skim milk.

Based on the results, DeBoer and his colleagues suggest that current recommendations on milk be reconsidered, especially since the relationship between milk and the calories that children consume may be more complicated that previously thought. They write:

The logic behind these AAP recommendations is that if children drink reduced-fat milk, this results in overall fewer calories consumed. It has been well established that as compared to traditional plant-based diets, Western diets high in saturated fat are associated with increased weight gain. In both children and adults, key contributors to the current obesity epidemic are the high-fat diets increasingly consumed worldwide. Encouraging consumption of low-fat/skim milk instead of high-fat milk promotes a reduction of 5.5–22.5 g of fat (50–202 calories) daily among children drinking one to three cups of milk per day.

(MORE: Mom Puts Her 7-Year-Old Daughter on a Diet, then Writes About It in Vogue)

The added calories in milk may not end up being such an important contributor to weight gain, especially among young children. And there are other, better-documented ways to helping youngsters to keep weight down. “There are other interventions that pediatricians can advocate for that have a better evidence basis than this one,” says DeBoer. “With the limited amount of time a pediatrician or family practitioner has with a patient, emphasizing other points that are more likely to be efficacious may be a better approach than focusing on this one, which logic would dictate would be effective, but this observation suggests it may not be.” Pediatricians could be focusing on recommending less television viewing, for instance, and more physical activity, as well as advising parents to limit children’s consumption of juices and sugar-sweetened beverages.

DeBoer agrees that studies designed to look directly at the link are needed. “The big caveat here is that if you were able to keep the rest of your diet exactly the same, switching from whole milk to skim milk should be able to decrease your total number of calories, but those don’t exist in isolation. I do think that going back and thinking which strategies to fight weight are going to be effective is an important step. I do think we should look at this again, certainly with more detailed randomized studies,” says DeBoer.

(MORE: Q&A with the White House Chef on Healthy Eating)

8 comments
HF75
HF75

I agree with JamesWarden, besides I am quite sure that if they had compared soy milk drinkers to dairy milk drinkers, the results would have been quite different. The kids would get their calcium from the (unsweetened) soy drink without the high insulin response caused by milk and other dairy products

JamesWarden
JamesWarden

It's not the fat in milk that makes these kids grow fat, it is the whey. Low fat milk has more whey than full fat. The lower the fat, the more the protein amount including whey. Whey activates insulin and growth hormone. If you overfeed on whey, you will break the insulin sensitivity of these kids and they will grow out of what is reasonable. What these kids need once they are on solid foods is good fats (Omega-3 DHA), proteins + vitamin D!! The carbs are also triggering an insulin response akin to whey, which is a growth trigger. Moreover, cow milk whey is designed for the cow babies that have a hugh need for rapid growth! Feeding kids with cow whey is absurd. Stop this madness, and give your kids some real healthy oily fish and grass fed meats! it is simple.

Modunn
Modunn

Absolutely  - have no idea why anyone would give low fat milk to adults far less children! For far too long we have been fed (excuse pun) the notion that low-fat milk helps you lose weigh. It certainly does nothing to help you lose weight!

CaloriesProper
CaloriesProper

Switching from dairy fat to [insert any low-fat food item here] doesn't work.  Think anyone will switch back to drinking regular milk?  I don't.

CTwildheart
CTwildheart

As an adult I drink 1% because I like the taste better.  For children, I would almost never put them on any kind of diet - but I would make sure they eat healthy (healthfully?) and stay active.

DarlieneHowell
DarlieneHowell

I would like to recommend the free NAAFA Child Advocacy ToolkitSM (CATK) to assist you looking at programs. The total health of our nation's children is a serious responsibility.

The NAAFA Child Advocacy Toolkit shows how Health At Every Size® takes the focus off weight and directs it to healthful eating and enjoyable movement. It addresses bullying, building positive self-image and eliminating stigmatization of large children. Additionally, the CATK lists resources available to parents and educators or caregivers for educational materials, curriculum and programming that is beneficial for all children. It can be found at: http://tinyurl.com/7ma5bml

mtngoatjoe
mtngoatjoe

Parents really need to understand how many calories are in juice drinks. Buy frozen juice and double the amount of water it says to add. This will help. Also, busy parents need to figure out a way to get their kids to be more active. Swimming is one of the best activities for kids. BUT, swim lessons aren't a substitute for letting kids play in the pool for a couple of hours. My daughter's swim lessons are half an hour, and she spends more time hanging onto the side of the pool than she does swimming. So, I try to take my daughter to the pool at least once a week to let her play. Since she can't pass the swim test yet, I have to get in the water with her. It's work for me, but the time spend with her is really worth it.

I've found that if I keep the TV to 1 Dora a day (22 minutes) and get her to the pool at least once a week (and preferably twice), her behavior is WAY better.