Is eating fat really bad for you?

Having explored whether you should you make fruit and veg your main source of carbohydrate and why you should eat some quality protein with every meal in my previous two blogs, this penultimate instalment of the ‘7 Habits of Good Nutrition’ series focuses on the third macronutrient...

 

Fat.

 

Habit #6: “Eat a mixture of natural fats each day”

Over the years dietary fat has been on a rollercoaster ride of public perception and remains a controversial topic among nutrition experts. At some point we've all been told that dietary fats are bad for us and that we should minimise them in our diet, yet at the same time we all know of someone who champions a high fat diet as a means of maximising health and athletic performance (for example, long time PH drinker Penny Barker, who went LCHF when training for Race Across America this summer)


So, is fat good or bad?

At Porsche Human Performance, we sit somewhere in the middle. Fats play an integral role in our diets and that cannot be argued with. Within the body, dietary fats have a number of key functions including...

  • The formation and growth of cell membranes and tissues of the brain and nervous system.
  • The provision of energy for low intensity activities.
  • The production and regulation of hormones.
  • Supporting immune and reproductive function.
  • The transportation of fat-soluble vitamins (A, D, E and K).

So we definitely need fat in our diets. With this in mind, what are the best foods to get our fats from?


The best sources of dietary fat

You’re probably aware that there are different types of dietary fat. Each type is distinguished by its chemical structure and this determines how they act within our bodies.

Essentially we have saturated and unsaturated fats, with the latter divided further into mono- and poly-unsaturated fats.

Here's a list of food sources from which we encourage our athletes to get each type of dietary fat...

 

Saturated

  • Minimally processed animal products (including natural cuts of meat, eggs and dairy products)
  • Dark chocolate (>80% cacao)
  • Coconut oil


Poly-unsaturated

  • Oily fish (including salmon, mackerel, sardines, herring, trout)
  • Fish oil supplements (look for those which provide 1000-3000 mg combined EPA & DHA)
  • Flaxseed 
  • Raw nuts, seeds & natural nut butters


Mono-unsaturated

  • Olives
  • Olive oil
  • Avocados
  • Raw nuts, seeds & natural nut butters


You’ll note that these foods are all pretty natural and minimally processed. This is a key concept with dietary fats (more on that later).

At PHP, we encourage our athletes to get their total dietary fat intake from an even split of these three fat types. Most people tend to get sufficient amounts of saturated fat without really trying, so making sure these saturated fats aren’t consumed in excess and incorporating more mono- and poly-unsaturated fats into the diet is often the main target here.

So you’re saying I should eat saturated fats - aren’t those bad for you?!

This is a controversial issue but we have our own stance on the matter. There's evidence which suggests excessive intakes of saturated fat can cause a whole host of health problems. However, one key consideration here is the excessanything can be harmful when consumed in excess.

When we look at the foods from which people tend to get their saturated fat, we see an interesting picture; a whopping 79% of the saturated fat consumed in a modern Western diet comes from processed foods (which we would typically discourage people from eating anyway). 

It’s likely that some of those animal products in the remaining 21% would be processed meats, which are often best avoided too. PHP-recommended fat sources make up less than one fifth of the total saturated fat intake!

This begs the question, is it the saturated fat in these foods which is the problem or is it all of the other processed ingredients, a lack of accompanying nutrition and an ease of overconsumption with these types of food?

Rather than the conventional view of "saturated fat = bad" and "unsaturated fat = good", for us it’s more a case of "processed fats = bad" and "unprocessed fats = good". 


Saturated or unsaturated? How to tell...

You can tell whether a food is higher in saturated or unsaturated fat by reading the nutritional information on the label like the one below:

How to tell whether fats are saturated or unsaturated


The two numbers we’re interested in are those next to ‘fat’ and ‘saturates’. Here we can see that this is a pretty fatty food, containing 24.6 g per 100 g, of which just 2.4 g is saturated fat. So, roughly 10% of the fat in this food is saturated and 90% is unsaturated. Whilst we don’t get any further breakdown of these unsaturated fats to mono- or poly-unsaturated levels, this information can be useful for balancing the proportions of different fats in our diet.


A quick word on the Omegas

When talking about fats, you might have heard about Omega-3 (and perhaps Omega-6) fatty acids too. These are further subdivisions of poly-unsaturated fats and, again, based on their structure they each have different effects on our bodies.

Broadly speaking, Omega-3s are considered to be very beneficial to our health whilst Omega-6s can potentially be harmful.

Historically, our human ancestors lived off Omega-6 to Omega-3 ratios close to 1:1. Nowadays, the ratio in typical Western diets is more like 20:1. This major imbalance has played a role in the development of cardiovascular disease, certain cancers and diabetes. Therefore, taking steps to optimise our Omega-3 to Omega-6 ratio is a wise idea.

The worst culprits in this respect tend to be Omega-6 rich vegetable oils used for cooking at home and in fast food joints. They're also found in the additives in many processed foods like sweet and savoury snacks. With this in mind, here are three tips we give for improving your Omega-3 to Omega-6 ratio...

  1. Eat plenty Omega-3 rich foods like oily fish, fish oils and flaxseed.
  2. Minimise processed food intake (especially fried, fast and snack foods).
  3. Stick to coconut or olive oil when cooking at home.

So (contrasting the conventional beliefs of many) we’re fans of fat, provided it comes from the right sources. But - and it’s a big but - this isn’t the green light to go and eat the whole jar of almond butter and inhale the entire cheese board. Though healthy, essential parts of our diet, natural fats are still very high in calories.

Per gram, fats contain 9 calories compared with carbs and proteins which both contain 4 calories per gram. This doesn’t mean we should avoid high fat foods, just rather that we need to moderate our portion sizes to make sure our calorie intake stays in check.

Whereas for carbs and proteins we used fist- and palm-sized portions respectively, for fats we say to stick to 1-2 thumb sized portions. This would roughly equate to a handful of raw nuts, half an avocado or a tablespoon of olive oil.


What's the best time to consume fat?

Like with carbs and proteins, it's worth looking at when might be the best time to consume your dietary fat. This is more of a minor consideration in the grand scheme of things but can be worthwhile when you've optimised other aspects of your diet.

The easiest way to think of optimal timing for eating fat is that it's the opposite to carbs. Meals high in both carbs and fat tend to be very high in calories and very easy to over-consume. Combining fats with carbs can also slow the rate of carbohydrate digestion and reduce the effectiveness of pre/post-exercise carbohydrate as a performance and recovery aid.

With that in mind, higher carb meals should be lower in fat and higher fat meals should be lower in carbs. So, identify the meals where it might be ideal to go higher carb (e.g. around exercise) and lower the fat content, then in other meals and snacks you can switch the proportions in favour of fat.

Jack at Porsche Human Performance.


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Any thoughts?

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2 comments from fellow athletes

  • Chris: July 04, 2017

    Recently seen advocado oil. Is this a good alternative to coconut anand olive?

  • Ray Hasler: July 03, 2017

    Good fats from veg sources ok. Animal fats a big no no for me. I have been Vegan for 27 years and took up running at 58. I now have 89 marathons under my belt including 11 completed 100 mile ultra`s. You may like to read Udos Erasmus book called Fats that heal. Fats that kill. He is the worlds expert on dietry fats. He also came to Britain to stage some talks called. Ban The Pan.which basically stated that no matter how good the oil was that you used in your stir fry all would turn to trans fatty acids within minutes.Coconut oil had a higher break down point. Just a thought. Scott Jurek won the Western States 100 mile race in California in 7 consecutive years. A vegan athlete.