DNAFit genetic nutrition report FAQs [Part 1]

We've DNA tested a lot of people at DNAFit over the years (over 36 000 in fact), and we've also received a lot of questions regarding the contents of our reports. Here's a break down of some of our most frequently asked questions. We hope you find some of the answers you're looking for!

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Part 1: General Questions, Carbohydrate and Saturated Fat Sensitivity

The DNAFit Nutrition Report is specifically laid out to help you structure your diet accordingly by linking what you eat to your genetics. The basis of this starts at your ideal diet type: Low Carb, Low Fat or Mediterranean Diet and then gives you insights into your body’s response to a whole spectrum of factors: carbohydrate and fat sensitivity, micronutrient and vitamin needs, detoxification ability, salt, caffeine and alcohol response and lactose intolerance and coeliac predisposition.

By undergoing DNA testing, you will find that your genes can tell you a lot about your nutrition and  how to eat genetically. Perhaps you’ve always wanted to know the best diet for you to do, or how you can live healthier. If so, then a DNAFit test is for you.

However, genetics is still an emerging science that many people are only getting to grips with. Due to this, it is sometimes difficult for people to understand their genetic profile and the interaction between genes and nutrition. We have compiled the most frequently asked questions regarding our DNAFit Nutrition Report to make it easier to understand what DNAFit can do for you. 

Frequently asked questions 

I’ve come back as having a higher than average risk of having coeliac disease. This means I should avoid gluten, right?

Not necessarily. Coeliac disease is an autoimmune condition that affects the small intestine. If people with coeliac disease consume gluten, then they get a nasty reaction in their microvilli – small, finger like structures in their small intestines – that can cause them to atrophy. This is bad news, because it makes it harder for that person to absorb vitamins and minerals. We know that there is a genetic link to coeliac disease, with about 99% of people with coeliac disease having at least one of the HLA DQ2 or HLA DQ8 variants. So having one of these variants increases your risk of developing coeliac disease, but it’s also important to keep in mind that the vast majority of people with these variants will not have or develop coeliac disease. As such, if you do have those variants, we would recommend that you monitor for symptoms of coeliac disease, such as rapid weight loss and lethargy, and, if these symptoms occur, it would be worthwhile having further tests done.


Another thing I’ve noticed is that our test says I’m not lactose intolerant, but I know I am. Your test must be a load of rubbish then?

Not at all! With the lactose intolerance portion of our test, we’re looking at a gene called LCT, which determines whether you can produce lactase, the enzyme that digests lactose, into adulthood. Approximately 65% of the world’s population lose the ability to produce this enzyme after weaning, although this number is lower in the UK and the US – closer to 10%. If you have at least one T allele for this gene, you have the genetic ability to produce lactose, which means we would class you as lactose tolerant. However, it is possible that you have secondary lactose intolerance, which can be due to a number of other things, including IBS. You might also be intolerant or sensitive to some of the protein found in milk, most commonly casein.


I’ve been classed as a fast metaboliser of alcohol – does this mean that alcohol is bad for me?

No, it doesn’t. In the alcohol sensitivity section of our report, we’re looking at how quickly you can metabolise alcohol. We split people into two different groups; slow metabolisers and fast metabolisers. Fast metabolisers break down alcohol quicker, so it’s present in their blood for a shorter period of time, whilst in slow metabolisers it’s present for longer. Research suggests that slow metabolisers who consume moderate amounts of alcohol get a cardiovascular protective effect from this alcohol – the type of people for whom a glass or red wine a day might be good for. This effect isn’t present, or at least is reduced, in people who are fast metabolisers of alcohol. So it doesn’t mean alcohol is bad for you, just that it’s perhaps not as good as it is for slow metabolisers.


You also recommend that I have 3g of omega-3 per day. Where can I get this from?

Your best bet is oily fish; 150g of salmon has around 3g of omega-3 in it. However, many people don’t like oily fish, or at least don’t like it enough to want to have it every day. In this case, it might be sensible to have an omega-3 supplement to hit your targets.


Why don’t you tell me how many calories I need?

When it comes to how many calories you require, this is largely determined by your lifestyle, more so than your DNA. For example, identical twins have the same genes, but if one is running a marathon and the other is sat at a desk all day, their caloric needs are very different. Similarly, if one wanted to increase their muscle mass, whilst the other was looking to lose fat, they would need different caloric intakes. As we are a genetic testing company, we can only really give you advice on aspects altered by your DNA, of which caloric needs aren’t.


What does it mean if I have a high sensitivity to carbohydrates? 

When we’re looking at your sensitivity to carbohydrates, what we’re saying is that the more sensitive you are to carbohydrates, the more likely you are to develop type-II diabetes or gain excess fat with a high level of simple carbohydrates in your diet. In essence, the higher your sensitivity to carbohydrates, the more you want to focus on fruits and vegetables as the main source of carbohydrate in your diet.


Carbohydrate sensitivity 

Do I need to be on the ketogenic diet?

This is a lifestyle choice and therefore would be up to each individual to decide. We however don't recommend consuming less than 25% of your total calories from carbohydrates as less than this is typically not sustainable and could lead to various long term consequences. When you go onto the ketogenic diet initially you will lose weight because you are eliminating an entire food group and essentially the calories from that food.

However, as time passes, your body loses the ability to digest and metabolize carbohydrates due to lack of exposure. There when you have obtained your gaol and you start to revert back to a "normal" diet and consume more carbohydrates your body will only digest and metabolize the amount of carbohydrates it was used to receiving and the rest would be stored as fat which often then leads to rebound weight gain. Lack of exposure to carbs will also lead to a decrease in insulin sensitivity so upon reverting back to a "normal" diet, the decrease in insulin sensitivity and increase in carbs combined could increase your risk for type II diabetes.

Another consequence of decreasing carb intake is then having to increasing either protein or fat intake. By increasing protein intake there is often an increase in saturated fat (SFA) intake which can result in an increase in low-density lipoprotein (LDL) and total cholesterol which increases your risk for cardiovascular disease. Increasing fat intake in the ketogenic diet also results in an increase in SFA intake as the diet tends to include coconut oil, animal fat for cooking, etc which can result in an increase in LDL and total cholesterol which increases your risk for cardiovascular disease.

Read our article, Understanding carbohydrates, a low carb diet and the ketogenic diet planto find out more.


What is a carbohydrate?

Carbohydrates are the sugars, starches and fibers found in fruits, grains, vegetables and milk products. Carbohydrates are macronutrients, meaning they are one of the three main ways the body obtains energy, or calories. They are called carbohydrates because, at the chemical level, they contain carbon, hydrogen and oxygen.


Should I carb cycle? 

This is a lifestyle choice and therefore would be up to each individual to decide. However carb cycling could lead to energy depletion and effect training and general daily energy levels.


Should I carb load?

Carb loading is efficient before big competitive events but doesn't work for everyone. It is something you need to try out before big events and see if it works for you. If you are carb loading then you would only do it 3-4 days before the event. While carb loading you should decrease your training slightly. You want to increase carbs to 65-70% total calories (12-15g carbs/kg body weight) and decrease fat to compensate for the increase in carbs.


Are there some fruits that are bad for me?

No. Fruits contain fructose which is a natural form of sugar and should ideally be included in the diet in moderation, i.e. 2-3 servings of any fruit/day.


Are oats carbohydrates? 

Yes, oats are classified as carbohydrates. Oatmeal is made of hulled oat grains – groats – that have either been milled, steel-cut, or rolled. Oats give you a healthy dose of carbohydrates with an added bonus of fiber, but not all oats are created equal. Even though whole oats, quick oats and instant oats are all whole grains and all have about the same amount of carbohydrates and fiber, they rank differently on the glycemic index. Regular or quick oats have a score of 55, while instant oatmeal is all the way up at 83. This occurs because instant oats are designed to cook fast. Each flake is completely flattened during processing. Even though it’s still a whole grain, just as it cooks quicker, it also digests quicker, bringing blood glucose up quickly and then dropping it back down. Whole or even instant oats are a better option for you if you want to keep your blood sugars at a stable level and improve satiety.


How can I decrease the GI of high GI foods?

  • Eat oats and other starches at room temperature or as cool as possible. The hotter the starch the higher the GI. As starch cool down the GI will decrease. When starches are cooked and then cooled, the crystalline structure within the food changes to resistant starch which is more difficult to digest. Thus cold cooked starches, (eg boiled, cold potatoes in a potato salad) have a lower GI. This is especially true for maize meal. Thus cooked cold maize porridge has a lower GI than the hot freshly prepared porridge.
  • Add legumes to meals to lower the GI. Dry beans, peas and lentils, tinned beans, bean soup, and textured vegetable protein, will all lower the GI of a meal.
  • Select foods that are less ripe, for example a firm, yellow banana has a lower GI than a soft, ripe, mushy banana.
  • Fiber - Low glycemic index foods include fruits, vegetables, and whole grains. In general, the more fiber in a food, the lower the glycemic index.
  • The GI of a food is different when eaten alone than it is when combined with other foods. When eating a high GI food, you can combine it with other low GI foods to balance out the effect on blood glucose levels.


What is resistant starch? 

Resistant Starch (RS) is starch, including its degradation products, that escapes from digestion in the small intestine of healthy individuals. RS passes through the small intestine intact and is then fermented in the large intestine, producing short chain fatty acids (SCFA) which serve as an energy source for colonic cells. Foods that increase the amount of SCFAs in the colon are thought to be beneficial to health by helping to prevent the development of abnormal cells in the gut.

RS is naturally present in some foods such as bananas, potatoes, grains, pulses and seeds and is also produced or modified commercially and incorporated into some food products."


It shows that I have a low sensitivity to carbs but a coeliac predisposition. Don't those results contradict each other?

No they don't. Carbohydrate sensitivity looks at the metabolism of carbohydrates and what your risk would be regarding weight gain and type 2 diabetes based on carbohydrate intake. Coeliac predisposition does not look at carbohydrate metabolism or either of the previously mentioned risk factor. For coeliac predisposition we look at the HLA (human leukocyte antigen) which allows the immune system to distinguish between self and non-self cells in the small intestine.


What are refined carbohydrates?

This will help us determine your risk for developing coeliacs disease. Even if you are at risk for developing coeliacs disease you don't have to eliminate gluten. You won't cause coeliacs disease by eating gluten containing products as coeliacs disease is an autoimmune disease and is not caused due to intake. There the 2 components are not related.

Carbohydrates that have been processed or have added sugar and have their natural fibre removed. Eg. white bread, white rice, white pasta, baked goods, sweets, chocolates and sodas.


What are unrefined carbohydrates? 

Carbohydrates that have not been processed and that contain fibre. Eg. brown/whole wheat/ seed loaf bread, brown rice, whole wheat pasta and fruit and vegetables.

Do whole grains affect my cholesterol?

Whole grains help to decrease cholesterol and have been shown to be cardioprotective. The way in which whole grains protect the heart is not fully understood; the fiber in whole grains may be responsible for protecting the heart. In a study of nearly 43,000 men, those who ate the most whole grains had an 18 percent lower risk of heart disease than those who ate the least. Eating bran made an even greater difference; the group that ate the most bran had a 30 percent lower risk of heart disease than those who didn't eat bran. In a study of more than 200 women with heart disease, those who ate six or more servings of whole grains a week had less buildup of plaque in their arteries that those who ate whole grains less often.


Saturated fat sensitivity 

Do men really need low to normal cholesterol levels? Won't it affect their testosterone?

Currently, the effect of testosterone on cholesterol isn’t clear. Some researchers have found that testosterone lowers both high-density lipoprotein (HDL) and low-density lipoprotein (LDL) levels. Others have found testosterone doesn’t affect either of them. Studies on the effect of testosterone on total cholesterol are also contradictory. On the other hand, several studies have found testosterone has no effect on triglyceride levels. So, testosterone can’t lower triglyceride levels, but researchers don’t know how or even if it affects total, HDL, and LDL cholesterol.


What is a saturated fat?

From a chemical standpoint, saturated fats are simply fat molecules that have no double bonds between carbon molecules because they are saturated with hydrogen molecules. Saturated fats are typically solid at room temperature. It is typically known as a "bad" fat found in animal fat, full fat dairy, cream, butter, lard, gee, palm kernel oil and coconut oil (and coconut based products).


Are unsaturated fats bad?

Unsaturated fats are typically known as "good" fats and have various health benefits. Unsaturated fats come in two main forms, polyunsaturated and monounsaturated fatty acids. Replacing saturated fats with monounsaturated fats has a cholesterol lowering effect. There are two main types of polyunsaturated fats, including omega-3 and omega-6 and both of these forms have health benefits. Omega-3 has been shown to be protective against heart disease in a number of ways, including lowering blood triglyceride levels and blood pressure.

Research has found that people who have a higher intake of fish have a lower risk of developing heart disease. Omega-6 has been shown to decrease the risk of heart disease when they are consumed in place of saturated and trans fats. Unsaturated fats help the body absorb vitamins known as fat-soluble vitamins. When someone consumes a fat-soluble vitamin, the body absorbs the vitamin and stores it in the fatty tissue. Unsaturated fats control the structure of the cell wall. Each cell has a wall to support the cell, determine the shape of the cell, control the rate of cell growth and resist water pressure.


Which one is better, butter or margarine?

Butter contains SFA where margarine contains TFA. Both these FA should be minimised in the diet. Therefore one is better than the other. They both have negative components.

Monounsaturated fatty acids (MUFAs) are fatty acids that are missing one hydrogen pair on their chain. They are associated with lowering LDL cholesterol and total cholesterol while at the same time increasing the production of the 'good' cholesterol, HDL cholesterol.


What is the difference between mono and polyunsaturated fats? 

You find monounsaturated fats in vegetable oils like canola, peanut and olive oil, as well as in nuts. These fats are usually liquid at room temperature. Polyunsaturated fatty acids (PUFAs) are missing two or more hydrogen pairs on their fatty acid chains. They trigger lower blood/serum cholesterol as well as lower LDL and HDL production. You can find these fats in vegetable oils like corn, sesame, sunflower, safflower and soybean, as well as in fatty fish. These fats are usually liquid at room temperature.


What is the difference between refined and unrefined (whole) grains?

Whole grains include all three parts of the grain kernel: bran, germ, and endosperm. The bran is the outer covering that protects the seed. It contains fiber, B vitamins, and minerals. The germ contains the embryo, which, if fertilized, will sprout into a new plant; it contains B vitamins, vitamin E, minerals, and some protein. Both the germ and the bran contain many phytonutrients -- health-promoting plant compounds -- including polyphenols, phytoestrogens, and antioxidants. The endosperm is the largest part of the kernel, which supplies energy to the growing seedling. It contains carbohydrate, protein, and small amounts of vitamins and minerals. 

When grains are refined, the bran and some of the germ are removed, leaving the starchy endosperm. Whole grains have various health benefits like lowering cholesterol, whereas refined grains only provide a fast form of energy and contribute to weight gain if consumed in excess.


Do nuts contain saturated fats?

Nuts do contain small amounts of saturated fat. 

Many companies such as 23andMe, AncestryDNA and Helix offer a wide range of tests that provide you with genetic analysis. However, the DNAFit reports on fitness and nutrition, or diet, offer a comprehensive look at how you can personalise your fitness to live healthier and train more efficiently than ever before.

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