Fats Debate – Sorting the Truth from the Myths
In celebration of Dietitians Week, I am writing my second blog of the week – this time, all about the fats debate. Dietitians Week is all about raising awareness of the work Dietitians do and their unique skills. Dietitians are truly the gold standard when it comes to nutrition and nutritional advice. To read about the difference between Dietitians, nutritionists and nutritional therapists, visit the Trust a Dietitian website.
Tuesday 10th June saw us taking Twitter by storm, trending with the hashtag #rduk. Dietitians, nutritionists and others interested in nutrition took part on a chat all about fat, aiming to share evidence based practice and inform the nation about nutritional truths. This blog is a summary of the questions and key points raised / discussed. For more information, you can go to the rdchat website, and you can see previous Twitter chats here too.
In light of recent research, should we change the way we look at saturated fat?
- The recent study (Chowdury et al, 2014) found that there was no evidence that saturated fat increased risk of coronary disease, or that polyunsaturated fats had a cardiprotective effect – a good summary of this study can be found on the NHS Choices website
- However, this new ‘evidence’ is not strong enough to change recommendations about saturated fat
- We have 35+ years of research showing the link between saturated at and cardiovascular disease – this is not something that should be dismissed quickly
- Saturated fat intakes should still be kept as low as possible (and definitely below 11% of total energy intake) – as a nation we are eating above the saturated fat recommendations, at 12.7% of total energy intake.
- Saturated fats are still fats and are therefore high in energy – containing a massive 9kcal per gram (compared to carbohydrates which contain 4kcal per gram). Therefore if weight loss / weight maintainence is your goal, cutting down on total fat will help
- Let’s stop demonising single nutrients – it’s the balance of the diet and how everything interacts that’s important
- It’s vital and future research is credible and represented correctly, otherwise more public confusion is caused
- It’s what you replace the saturated fat with that’s important too!
What’s the deal with coconut oil?
- There are no quality peer reviewed data / studies on coconut oil and health – more information is testimonial based, which is not classed as evidence
- One good study (RCT) on MCTs – medium chain triglycerides (the major fats in coconut oil) showed no difference on blood lipids compared to corn oil
- Although coconut oil is plant based, it is 92% saturated fat – this is the highest amount of saturated fat of any fat/ oil
- The profile of the individual fatty acids in coconut oil is different to other classic saturated fats – mainly lauric (44%) and myristic (16.8%) fatty acids, so it may not be as bad as other saturated fats, but more good quality studies are needed
- Whilst coconut oil has a different effect on HDL:LDL ratio (ratio of good:bad cholesterol) than other saturated fats, not enough evidence is known about these benefits, and the message is confusing
- Coconut oil is still a fat (9kcal per gram) – so if you’re trying to lose weight / maintain a healthy weight, use in small quantities
- Coconut oil is expensive – and there is no evidence to suggest the benefit outweighs the cost
- Until we have some robust evidence, olive oil, rapeseed oil and groundnut oil are better options, as they contain more unsaturated fats
Is butter better of worse than spreads?
- Everything is ok in moderation – so a small amount of butter will be fine – but we shouldn’t be promoting large amounts of butter
- Weigh up the amount you use through the day. If just in a sandwich, that would be fine, but if you’re having it on toast, in a sandwich and to make up a white sauce, consider switching to a spread
- Portion size is key!
- Spreads are not hydrogenated anymore (as they used to be in the past, pre 1994), so no issues with trans (bad) fats. Butter however, still has 3-4% trans fats, as well as a whole lot more saturated fat. Check out The Fat Information Service for more information.
Tips for getting the balance right
- Include a variety of healthy fats – peanut butter, seeds, nuts, oily fish
- Cook oils on moderate heat to avoid getting to smoking point, as trans fats are made at high temperatures
- Mediterranean diet has been showed in numerous good quality studies to be good for the heart! Oily fish, olive oil, avocado, nuts, seeds, fruit, vegetables and wholegrains
- Portion size is really important
- Include a handful (25-30g) of nuts / seeds (unsalted) each day – healthy fats, protein, fibre, vitamins and essential minerals
- Consider what is replacing the fat in your diet – consider plant-based foods, not beans / lentils / pulses and low fat dairy foods
On a personal note, I don’t use coconut oil – I use extra virgin olive oil in cooking. Try not to let your oil reach smoking point when cooking. This will prevent trans fat (bad fats) from forming. Extra Virgin Olive Oil has a higher smoking point that other oils, meaning it may be better suited (and healthier) for cooking at high temperatures. On my toast and sandwiches I use a supermarket own olive spread, which contains around 40% of the fat in butter.