Letters Dietary fats: a new look at old data

Dietary fats: debate should consider foods rather than nutrients

BMJ 2016; 353 doi: https://doi.org/10.1136/bmj.i2884 (Published 24 May 2016) Cite this as: BMJ 2016;353:i2884
  1. Rosemary A Stanton,
  2. public health nutritionist
  1. University of New South Wales, Sydney NSW 2052, Australia
  1. rosemary.stanton{at}westnet.com.au

The debate over types of fats stumbles, as it doesn’t look at the foods containing them.1 In studies such as the Sydney Diet Heart Study in the 1970s, participants were given a margarine with large amounts of trans fatty acids.2 It’s little wonder the results were negative.

Basing any recommendation on a single nutrient’s content is meaningless. For example, 35 g of cheese, 35 g of white chocolate, 70 g of crisps, 90 g of roasted cashews, a small (145 g) rump steak, a tablespoon of lard, 50 g of polyunsaturated margarine, a small custard tart, and 15 g of hollandaise sauce all contain the same amount of saturated fat.3

These foods have little else in common, and judging a diet by its saturated fat content ignores other attributes (or lack of them) in particular foods.

It makes much more sense to judge a diet by the total eating pattern, looking at foods rather than nutrients. Good evidence shows that a healthy diet has plenty of vegetables; some fruit, pulses, whole grains, nuts, seeds, extra virgin olive oil, fish or seafood; modest portions of lean meat or poultry; and dairy.4

A healthy diet also contains only small amounts of “discretionary” foods and drinks, commonly called junk food. This is the diet our guidelines recommend,4 but it sadly bears little resemblance to what people currently eat. In Australia, 35-41% of kilojoules come from discretionary food and drink.5 That’s the major problem. It won’t be fixed by giving the nod to saturated fat.


  • Competing interests: None declared.


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