Should I eat more or less dairy if I want a low emission diet?
Australian adults consume around 1¾ serves of dairy foods like milk, cheese and yogurt each day. Each serve is equivalent to 250ml of milk.
This is less than the minimum 2½ serves of dairy (or alternatives) recommended for those in the 19-50-year age bracket by the Australian Dietary Guidelines. Recommendations are even higher for teenagers at 3½ serves and go as high as 4 serves per day for women above 70.
At the same as there are recommendations to increase dairy intake, there are also numerous recommendations focused on sustainability that suggest dairy foods should be minimised or kept to only one serve per day. So, to be healthy and sustainable, how much dairy should we be consuming?
CSIRO research recently published in the European Journal of Nutrition examined a subset of 1732 Australian adult diets with above average diet quality score (37% higher) and below average greenhouse gas (GHG) emissions (43% lower). The amounts of dairy foods in each diet as well as the nutrient profiles were assessed.
This subset of diets is of interest because it reflects the dietary habits of everyday Australians with more desirable dietary characteristics. These are habits that could be realistically adopted by Australians who presently have diets with poorer quality or higher GHG emissions.
Can a lower GHG emission diet include dairy?
The research found that 90% of these healthier and lower GHG emission diets included dairy foods. Milk was the most commonly consumed dairy food, followed by cheese and then yogurt. This is not surprising considering the long cultural tradition of dairy food consumption in Australia.
What distinguished this subset of diets was a much lower consumption of discretionary foods. These energy-dense and nutrient-poor foods are high in saturated fat, added sugars, added salt and alcohol. Cakes and biscuits, pizza, hot chips and soft drinks are a few examples of the many that are widely available.
According to the Australian Dietary Guidelines, most Australians consume too many discretionary foods instead of choosing foods from the Five Food Groups.
Is the recommended intake of dairy necessary?
The intake of dairy foods recommended by the Australian Dietary Guidelines may seem high. However, more than 300 of the healthier and lower GHG emissions diets in our sample achieved this level.
People in this group also had the greatest likelihood of achieving the Recommended Dietary Intake (RDI) of a broad range of nutrients, as defined by the National Health and Medical Research Council.
For example, 94% of these diets met the recommended daily intake for calcium, 97% for protein, and a similar percentage for vitamin B12.
In contrast, diets in our sample with only low levels of dairy food had much lower likelihood of achieving recommended nutrient intakes. Only 5% met the recommended daily intake for calcium, 72% for protein and 47% for vitamin B12.
Are dairy avoiders achieving recommended nutrient intakes?
Among our sample of healthier and lower GHG emission diets were 90 diets of dairy avoiders. On average, these diets included around 0.9 serves of dairy foods as well as 0.2 serves of non-dairy alternatives (e.g. soy, cereal or nut beverage).
While some people strictly avoid dairy foods due to a diagnosed intolerance, others are motivated by the advice of ‘wellness experts’ or friends to minimise dairy foods based on perceptions they are unhealthy or fattening.
We found that dairy avoiders rarely consumed sufficient dairy alternatives to make up for the avoided dairy foods. Only 7.7% of these diets met the recommendations of the Australian Dietary Guidelines for this food group.
Not surprisingly, the likelihood of achieving the recommended daily intake of a broad range of nutrients was also low. For example, 22% met the recommended daily intake for calcium, 74% for protein and 61% for vitamin B12.
In recent years, many new dairy alternatives have become available. These products are very helpful for people who are unable to consume dairy foods due to diagnosed medical conditions and they can also offer interesting variety for everyone.
If adequately fortified, dairy-alternatives can provide an alternative source of dietary calcium. However, dairy alternatives do not generally provide an equivalent profile of nutrients to dairy foods. Our results suggest there may be a need for greater awareness about this.
There are a lot of suggestions going around about lower GHG emission diets. The problem is that many are linked to poor nutritional and health indictors.
In the Australian context, lower GHG emission diets have better nutrient profiles when they include dairy foods at the levels recommended by the Australian Dietary Guidelines.