Food fashion has shifted away from low-fat in recent years. But with low-fat still the focus of public health messages, some are questioning whether such recommendations are right.
On Monday, a paper titled Three Daily Servings of Reduced-Fat Milk: An Evidence-Based Recommendation? was published in the Journal of the American Medical Association (JAMA).
The authors, David Ludwig and Walter Willett of Harvard Medical School, said: "Remarkably few randomised clinical trials have examined the effects of reduced-fat milk (0 per cent to 2 per cent fat content) compared with whole milk on weight gain or other health outcomes."
What has happened instead is a "presumption that the lower-calorie content will equate to a lesser likelihood of weight-gain".
But this, they contend, is not the case.
In fact, in their review, they point to numerous studies of young children, adolescents and adults that found the same or greater rates of weight gain with the consumption of reduced-fat milk compared with whole milk.
They reasoned that perhaps "people compensate or overcompensate for the lower calorie content of reduced fat milk by eating more of other foods".
The typical example is the extra biscuit or bit of cake with your low-fat latte. This is a double whammy, they say.
"A low-fat, high-glycemic diet may not only increase hunger but also adversely affect energy expenditure compared with diets with a higher proportion of fat."
But Kate DiPrima, an accredited practising dietitian and spokeswoman for the Dietitians Association of Australia, believes the message they are promoting is problematic.
"What really worries me [about these studies] is that they look at one item," DiPrima says.
Rather than looking at the milk "plus yoghurt and cheese, plus a pizza and something else," they blame low-fat milk.
The odd flat white on full-cream is fine, she says, but with seven in ten Australian men and more than six in ten women overweight, she fears people adding full-cream milk "on top of everything-else" may be harmful.
In an op-ed titled In Defence of Skim Milk American dietitian, Maryann Tomovic Jacobson also defended reduced-fat dairy:
"I don't choose skim milk for weight control, I drink it because I want to leave room more for healthier fats that come from plant foods and fish," she said. "For example, my morning oatmeal includes a handful of walnuts which adds a hearty 20 grams of fat, and that keeps me nice and satisfied. Do I really need to add milk fat on top of that?"
It's a fair point. And one that DiPrima and Australia's regulating bodies agree with.
"Our position is we're guided by evidence-based medicine," DiPrima says.
"The National Health and Medical Research Council regulates the guidelines and [for the updated guidelines released in February this year] they went through hundreds of studies... to make these recommendations."
The current guidelines recommend reduced-fat dairy for everyone over the age of two.
Regardless, reduced-fat dairy continues to cop criticism.
Ludwig and Willett say that to help palatability, many skim milks are sweetened. While sweetened reduced-fat milk lowers saturated fat by 3g it increases sugar by up to 13g a cup.
A separate Harvard study of 18,555 women has also found: "high intake of low-fat dairy foods may increase the risk of anovulatory infertility whereas intake of high-fat dairy foods may decrease this risk."
Based on the such studies, American doctor, author and director of the Arizona Center for Integrative Medicine, Andrew Weil says, "I no longer recommend choosing low-fat dairy products. I believe the healthier choice is high-quality, organic dairy foods in moderation".
Ludwig and Willett take this statement a step further. "Humans have no nutritional requirement for animal milk, an evolutionarily recent addition to diet," they write.
As for whether we need milk for bone health, they argue that the recommendations are likely to be overestimated and "throughout the world, bone fracture rates tend to be lower in countries that do not consume milk compared with those that do....
"Nevertheless, milk provides significant amounts of protein and other essential nutrients and may confer health benefits for children and adults with poor overall diet quality."
Indeed. Dairy contains calcium, protein, carbohydrate, vitamin A, vitamin B12, riboflavin, magnesium, potassium, phosphorous and zinc.
Over 80 per cent of Australians across all ages eat or drink a dairy food in any given day and each of us drink around 104 litres of milk a year.
That is unlikely to stop given the arguments on both sides, but which carton to choose?
"The key is small portions sizes, balance and to follow the guidelines," says DiParma's who herself opts for reduced-fat. Remember, she says, "it's not just looking at one food".
Ludwig and Willett, on the other hand, say: "The recommendation to replace whole milk with reduced-fat milk lacks an evidence basis for weight-management or cardiovascular disease prevention...
"The optimal level of milk consumption with likely vary among individuals, depending on overall diet quality."
- Sydney Morning Herald
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