Fat vs Sugar. Who can you trust?

I feel like I’ve had a big week this week. The weather here in Melbourne has also been a bit lousy, which is never good for one’s mood. Although, given that it’s currently winter here, it’s hardly surprising! Tuesday, with its gale-force winds and rain, was particularly unpleasant. I was grateful not to be in Canberra (Australia’s capital), though, where locals had similar winds, but a maximum of just 6 degrees Celsius.

I’m not usually one for watching long TV programs or movies. But on days like Tuesday, there’s nothing like cosying up to a hot drink and hot water bottle, and sitting down for some good TV.


Some of you may have heard of popular personalities promoting diets high in butter and other animal fats, and saying that sugar is ‘toxic’. Many of you have probably heard of the old ‘low-fat’ eating advice, which was recommended by health professionals a decade or more ago. This perspective saw fat as the enemy.

“Fat vs. Sugar” (links to full documentary) aired a few days ago here in Australia, and aims to answer this question once and for all. Is fat or sugar the enemy?

The BBC documentary follows two British medical doctors who are identical twins, as they set out to explore whether fat or sugar is worse for you.  One of the twins follows a high-fat diet for one month, while the other twin follows a low-fat, high ‘sugar’ (carbohydrate) diet for the same period. The show spends most of the time investigating the effects of the diets on the twins.

While I will be the first to admit that their experiment is far from being strong evidence, it does provide some good entertainment. I also find that sometimes, seeing something in real-life puts a more personal spin on the nutritional advice you read about (especially if you’re not a ‘numbers person’).



The short answer is:

Neither fats nor carbohydrates (carbs; what the documentary calls ‘sugars’) are ‘toxic’, they’re essential nutrients. We need to eat sources of both. The best way to do this is to follow a simple way of eating, rich in plant foods (see my post on what food to eat). 

Dietitians don’t recommend low-fat diets, they recommend minimising animal fats. Replacing animal fats with plant oils, such as in nuts and avocado, is recommended (see related post).

‘Extras’ foods, like ice-cream, cakes, chocolate, lollies, pastry, soft drink… have no part in our everyday diet. Save them for an occasional (read: not everyday) treat.


My first tip would be to get your nutrition (and health) information from reputable sources. Advocating a balanced view of healthy eating isn’t exactly the way to become a millionaire overnight. So often you find people with questionable qualifications out to make a quick buck proclaiming a certain part of food as ‘toxic’, or a ‘saviour’, and a secret conspiracy by nutrition professionals to hide this saviour from you ([dramatic music] ‘The Holy Grail that nutrition experts don’t want you to know about…’).

If you’re reading mainstream magazines, watching commercial TV, or reading the websites of certain cashed-up nutrition ‘gurus’, you’re probably not doing yourself a huge favour. I also would have a headache and feel very confused if I listened to these gurus’ latest wild theories, and there seems to be a new wild theory every few months! Advertisements and health claims of packaged, processed foods also often just worsen the confusion.


From Whitney E and Rolfes SR. Understanding Nutrition. 11th ed. Belmont: Thomson Higher Education; 2008.


Tips to find reputable health information:

  • Websites ending in .gov, .gov.au, .gov.uk are Government-published websites, which have no commercial agenda. These are highly trustworthy, and give a balanced view of the facts.
  • For readers wanting it simple, simple, simple!: Go to the Mayo Clinic, or Better Health Channel websites.
  • For readers wanting more detail, but still in simple language: Go to Patient.co.uk.


Tips to find reputable nutrition information:

  • Consult an Accredited Practising Dietitian or a Registered Dietitian (US/UK) for personalised nutritional advice. This is often rebatable from your health fund or insurance plan, but check with your provider for details.
  • The British Dietetic Association has some great fact sheets on a range of nutrition-related subjects.
  • Scoop Nutrition and the Nutrition Blog Network both have comprehensive directories of the blogs of Registered Dietitians.
  • If you’ve got a particular question about a diet, or a nutrition topic that’s been in the media, eDietitians has a range of articles written by qualified dietitians, written in a magazine style.
  • For a particular medical condition, often the association for that condition will also have some great information. For example, the Heart Foundation (Au/UK/US), Coeliac Foundation (Au/UK/US), and Diabetes Associations (Au/UK/US) are great resources. With smaller associations, it’s often a good idea to ensure that the person writing the article is a Dietitian, Medical Doctor, or Medical Researcher in that field, to ensure you can trust the information.


Got another website or other source of nutrition information that you can recommend? What do you think of the Fat vs. Sugar documentary?

I look forward to coming back next week and setting the facts straight about Omega-6 and seed oils, in Part 2 of my post series on Fats and Oils.

Hope everyone has a great weekend!


– Sonia.