How should you eat? More fats or less fats? Vegan or Paleo?
Despite all the uninformative dietary advice floating around the internet, we have some good news. Understanding your genetic profile can help you eat smarter because not all people digest fats the same way.
THE LONG AND SHORT OF IT (but read on for more details):
Digestion is a complex process and no two people digest things the same way. For instance, some people may have a greater risk of gaining weight if their diet contains a lot of saturated fat, while others may not gain as much. There are many variables that contribute to weight gain, and genetics may partly explain some of the variation between people. APOA2 and PPARG are genes linked to how the body uses fats.
Digestion is an incredibly complex process that involves many different cells’ enzymes and gut bacteria to break down the what you eat. It’s not something we really think about – unless something goes wrong, or we want to change the way we look or feel through diet.
Everyone digests foods differently – and genetics may partly explain this difference.
The actual process of converting food into energy your body can use is fairly similar between healthy people, but how motivated you are to eat and how your body uses the nutrients it extracts from food may be partly explained by your DNA.
Genetics can help to explain why some people perform at their best on a high-fat diet, versus others who gain weight from even a small increase in calories.
There are two genes in particular that Athletigen reports on that relate to fat sensitivity: APOA2 and PPARG.
Not all fats are created equal!
Have you ever wondered why olive oil, which is 100% fat, is considered healthy, while the ground beef in a hamburger, which is about 30% fat, is considered junk food? This is because not all fats are created equal. At their most basic level, fats are made up of molecules called triglycerides. Triglycerides are long chains of fatty acids and the structure of this chain determines whether the fat is liquid (like vegetable oils) or solid (like butter). What’s more, some fats can be liquid at room temperature, but when chilled, they’re solids (think, coconut oil).
Maybe you’ve heard of unsaturated, polyunsaturated, and saturated fats. But what’s the difference between these fats? It all has to do with the bond between the atoms within the long chain of fatty acids.
Fatty acids with a single bond are saturated. Higher levels of saturated fats are found in solid fats, like butter, cheese, and coconut oil. Those with a double bond between the atoms are called unsaturated fats, commonly found in vegetable oils.
In moderation, most unsaturated fats are good for you because they offer health benefits, such as:
- Improving heart health1
- Reducing depressive symptoms2
- Potential to assist with weight loss vs. saturated fat intake3
- Joint health & arthritis alleviation4
- Hormone production5
Excess saturated fat is bad for you because it can increase your levels of LDL-cholesterol (also known as ‘bad’ cholesterol as it may increase your risk of cardiovascular disease)6.
What about trans fats? I heard they’re bad.
Trans fats are a type of unsaturated fats that have a specific arrangement of hydrogen and carbon molecules. High trans fat oils, like partially hydrogenated vegetable oil are great for frying as they can reach a high temperature without smoking and give foods like fries and chips a delicious taste – but they’re terrible for your health, despite being a type of unsaturated fat. This type of fat should be avoided as it causes an increase in LDL-cholesterol – the ‘bad’ cholesterol that contributes to raising your risk of cardiovascular disease.
Why should I care about what type of fat I eat and how do my genes play a role?
The way that your body breaks down these types of fats can vary. At the most basic level, fat is broken down for energy when glucose (sugar) is low – and if not used, it’s stored as fatty (adipose) tissues. Your DNA also plays a role in how your body uses or stores fat. Your PPARG and APOA2 genes can affect how well your body deals with saturated and unsaturated fats.
Let’s get one thing straight: genes make the code for proteins, which are involved in every process in your body. Enzymes are proteins that cause reactions, like in the breakdown of fat. The variation within your genes can cause different levels of these proteins and enzymes, ultimately affecting how your body gets stuff done.
What does my APOA2 gene do?
Some people may not gain as much weight from a diet high in saturated fats compared to others. The research has shown that your variant of the APOA2 gene may affect how well you break down saturated fats7. This gene makes a part of HDL-cholesterol (known as ‘good’ cholesterol as it helps to clear triglycerides from the blood) that helps to clear excess cholesterol from cells. While the exact mechanism of the association between weight gain in response to saturated fat and APOA2 has not been confirmed, researchers think that it may not only affect how fat is broken down but how satisfied you feel after a meal8,9 too.
So, if you have the relatively rare GG variant of APOA2, found in about 13% of the population, and your diet is high (more than 22g) in saturated fat, there’s a higher-than-average chance that you may gain weight10. If you’re AA or AG, you risk of gaining weight when occasionally eating saturated fats may be lower than carriers of the GG variant.
Athletigen is fairly confident in the research surrounding this gene-trait association. Where sensitivity to weight gain from saturated fat is concerned, over 12 scientific papers have all shown similar results, among studied populations over 1,000 individuals from diverse ethnic backgrounds. Although this association hasn’t been confirmed in individuals of African descent, so this may explain any inconsistencies in your may experience.
What about PPARG?
The protein produced by this gene plays a role in breaking down fatty acids and energy production. Interestingly, this gene is more active in parts of your body that need more fat breakdown, like in your heart, in adipose (fatty) tissue, and in muscle. When this gene is activated, it results in higher levels of fatty acid breakdown and uptake of fat cells by energy11 – and because fat is so energy-dense, this is a good thing, especially if you’re an endurance athlete.
If you have the rarer GG or CG variant of PPARG, you may have improved unsaturated fat metabolism and gain less weight from this type of fat. If you’re CC you may experience faster weight gain (compared to GG or CG variants) if your diet is high in unsaturated fats.
Researchers used the ‘Mediterranean’ diet to test individuals’ response to unsaturated and polyunsaturated fats12. This type of diet is high in fruits, vegetables, whole grains, legumes, olive oil, and lean sources of protein, like chicken and fish rather than red meat. Three large studies have shown that if you have the ‘G’ allele – that is, if you’re a GG or CG – you may maintain a lower weight or even lose weight on the Mediterranean diet12,13,14 . What’s more, increasing your intake of unsaturated and polyunsaturated fats if you’re a GG or CG may increase your levels of HDL-cholesterol (‘good’ cholesterol) – a great way to keep your heart healthy.
We’re fairly confident in these findings, although it’s important to note that only European populations have been researched at this time, which might explain any differences between what your genes tell you and your experience.
So, tell me what to eat?
There are so many variables to consider when you’re formulating your diet. But one thing should be clear: you shouldn’t cut fat out of your diet completely. It’s important to balance your diet to ensure your body can function optimally. Taking into account your genetics, you can start to get a better picture of what may and what may not work for you.
Next week we’ll discuss how you can take your genetics and performance into account when deciding how to incorporate fat into your diet.
What does your DNA say about you? Find out at athletigen.com