Childhood obesity has become a major public health concern, with the prevalence tripling over the past four decades. In North America, nearly one in three children is now classified as overweight or obese, prompting health authorities to recommend dietary changes aimed at reducing this risk. One such recommendation is to switch from whole-fat cow's milk (3.25% fat) to reduced-fat milk (0.1-2% fat) for children over the age of two. This guideline has been widely adopted by healthcare providers, schools, and families alike.
Despite these recommendations, evidence regarding the relationship between cow-milk fat and childhood adiposity remains inconsistent. While reduced-fat milk is thought to help prevent excessive weight gain, recent studies have begun to challenge this assumption. Some observational research suggests that children who consume whole milk may have lower rates of overweight and obesity compared to those who drink reduced-fat milk.
Given the widespread consumption of cow's milk among children and its significant contribution to their dietary energy, protein, and fat intake, understanding the effects of milk fat on childhood obesity is crucial. This systematic review and meta-analysis aim to synthesize the available evidence on the relationship between cow-milk fat intake and childhood adiposity, with the goal of informing future dietary guidelines.
Background:
Childhood obesity has become increasingly common, and there has been a shift from whole-fat cow's milk to reduced-fat milk over recent decades. This shift has been driven by guidelines from organizations like the American Academy of Pediatrics, which suggest reducing fat intake in children to prevent obesity.
Objectives:
The primary goal of this study was to assess the relationship between cow-milk fat consumption and adiposity (fatness) in children aged 1-18 years.
Methods:
Researchers conducted a systematic review of observational studies from multiple databases up to August 2019, which examined cow-milk fat consumption and childhood adiposity. A total of 28 studies were included, of which 20 were cross-sectional and 8 were cohort studies. There were no clinical trials.
Results:
The meta-analysis found that children who consumed whole milk had lower odds of being overweight or obese compared to those who consumed reduced-fat milk. Specifically, the odds ratio (OR) for overweight or obesity was 0.61 in favor of whole milk consumption.
While most studies (18 out of 28) suggested a link between higher cow-milk fat intake and lower childhood adiposity, 10 studies found no significant association.
Conclusions:
Observational data suggest that whole milk consumption may be associated with a lower risk of childhood overweight, and obesity compared to reduced-fat milk. The findings challenge current dietary guidelines that recommend reduced-fat milk for children.
The study calls for randomized trials to better understand which type of milk minimizes the risk of excess adiposity in children. This review provides strong observational evidence but notes the need for randomized trials to confirm these findings.
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