Does your DNA really hold the secret to losing weight?   That was the headline in The Daily Mail recently, an article by Sadie Nicholas suggests that we should be considering the way our genes are, to determine our optimal diet.  DNA tests are all the rage, as is the trend for intermittent fasting, but how can they work together?  Kate Llewellyn-Waters is a Registered Nutritionist with a MSc. in Nutrition and the founder of The What IF Plan.


Here she shares some of her findings.

Intermittent Fasting and Nutrigenomics

Intermittent fasting is a powerful weight loss method, and it is very simple and easy to implement. It incites weight loss because of the restriction of food, followed by eating normally, and this can help stimulate your metabolism. Shorter fasts promoted by Intermittent Fasting (IF) have proven to increase metabolism, with one study reporting this increase in metabolism to be up to 14 per cent.

IF is also proposed as a more effective tool than long-term calorie restriction (e.g. a 1200 calorie a day diet), which can often wreak havoc on the body’s metabolism as it is constant deprivation and not just now and again like IF. Additionally, weight loss during long-term calorie restriction is often accompanied by muscle loss – and since muscle tissue is what burns through calories, having less muscle leads to a drop in your body’s ability to metabolise nutrients and food. But, IF keeps your metabolism operating efficiently by helping you hold on to your muscle tissue, especially if you make sure you include resistance training whilst fasting.

On fasting days, the body will be forced to use stored energy from the body, fat and stored glycogen (sugar), this obviously aids weight loss, but it also improves blood glucose, cholesterol levels and heart health. Studies have shown that intermittent fasting is highly effective for counteracting the vascular effects of ageing, and helps to reduce the “bad” LDL cholesterol, whilst increasing the “good” HDL cholesterol.

There are other benefits too, Research has shown that periods of fasting can help to improve life expectancy and decrease risks of diseases including Alzheimer’s disease and cancer. It has been suggested that this may be down to the mild “stress” that IF puts on the body. This stress acts as a “good” threat by improving the body’s cellular defence against potential negative molecular damage. IF also stimulates the body to repair tissues, which results in every organ and cell functioning more effectively.

How Nutrigenomics fits in is interesting. From how tall we are to how we react to carbs, we are all unique and our genes can have a huge impact on our health. Many studies have shown that genes influence how we process foods and the effect our daily diets has on our bodies and health.

Our individual genetic make-up can also influence how likely we are to gain weight, how our bodies deal with toxins and how we respond to exercise. Everyone has different needs, including micronutrient needs. So, one person may require more Omega-3 fats, vitamin B or C than their friend, for example, but they wouldn’t know this without taking a DNA test. Having this expert knowledge means we can then make some small changes to our diet for optimum health.

Those people with what is known as a “thrifty” genotype may be susceptible to gaining weight and body fat when they consume a high-carb diet. Yet, there are other people who can process carbohydrates quickly, and who can enjoy bowls and bowls of rice and not gain a pound.

DNA testing can make Intermittent Fasting even more beneficial  One 2010 study in the Wall Street Journal of over 100 women found that eating a genetically appropriate diet resulted in a whopping 287% more weight loss over 12 months than a eating a non-genetically appropriate diet.

Weight Management DNA tests look at genetic variants associated with weight management such as carb sensitivity, saturated fat sensitivity, gluten intolerance, lactose intolerance, caffeine sensitivity, salt sensitivity, optimal “diet” for weight loss, how much exercise you need for weight loss and the type of exercise and more.

Also, nutrigenomics and certain genetic variants can tell us about someone’s eating behaviour such as if they’re a snacker genetically or not – if so, they may find it easier spreading their food intake out and including smaller meals more often during IF rather than one big meal at the end of the day.

Nutrigenomics and IF is workable for even the busiest of people:

Simply register for a Weight Management DNA Test, which involves a very quick 60 second swab sample.

Meanwhile you can start including an Intermittent Fasting protocol in your lifestyle at any point. I swear by Time-restricted Feeding (TRF), which you may also know as the 16:8, and I credit this for my own weight management for the last 12 years – it really works and you never feel deprived. You basically fast for 16 hours (usually overnight) and eat in an 8 hour window. So, if you finish your evening meal at 7pm, your next meal would be 16 hours later at 11am. Or if you have to have breakfast you can eat breakfast say at 8am and just finish your last meal of the day earlier i.e. at 4pm. It is so flexible and fits round your life and what works for you.

There is also the slightly stricter Alternate-day Fasting (ADF) protocol where you eat 500-700 calories (women), 600-800 calories (men) one day and eat normally the next. I would suggest if you go for this stick to the higher end of the calories recommended, especially if you have a busy lifestyle. Both these Intermittent Fasting methods are evidence-based with many human studies supporting the protocols for weight loss and other health benefits.

Once you receive your DNA report, you can then include the suggestions on your fasting and non-fasting days. So, for me, it is important I follow a Low-Carb Diet for weight management and get my macronutrients in the correct ratio in my diet. I also know I have low-grade inflammation and 3g of Omega-3’s is paramount to counteract this inflammation. Uncontrolled inflammation = weight gain and potentially obesity. You may find you have a high requirement for folate and vitamin B-rich foods, same for cruciferous and allium vegetables, which are needed for the absence of a certain gene, which is so important for health.  We need to optimise detoxification, as exposure to too many toxins can slow down the liver’s functioning, leading to an increase of toxins within the body. The brain, breast and adrenal glands are organs with higher levels of fatty tissue, making these prime places for toxins to be stored. Unfortunately, this can lead to hormonal imbalances, creating a negative environment in the body, and leading to negative side effects like cognitive issues, anxiety and fatigue.

If your DNA report suggests you cut down on a specific nutrient such as caffeine (if you are a genetically a slow metaboliser of caffeine), make the changes gradually and you will soon feel the benefits.

Most of all make it work for you and your lifestyle – adapt the IF protocols to suit you. Then you will really be able to commit to the changes, which will have a positive long-term benefit on your weight and health!

Check out The What If Plan