Have you ever wondered why we are constantly bombarded by a constant stream of such fundamentally contrasting dietary advice via a plethora of media channels? We are inundated on a daily basis on the ultimate weight loss tactic or optimal nutrition breakthroughs; however, there essentially seems to be no clear-cut, comprehensive scientific consensus concerning the optimal diet, as the information drags you in polar opposite directions. In fact, the science increasingly points towards the fact that there is — no one diet that fits all approach—. We are all inherently different, which may explain why we respond physiologically differently to nutrition strategies and why no universally accepted diet can be identified.
Now, can you imagine a world where your DNA is encoded from birth? Where you will have access to intelligence of the diseases you are strongly predisposed to developing based on your DNA. Where dietary advice will be personalised to your individual genotype. This nutrition revolution is gradually becoming reality. The completion of the Human Genome Project in 2003 has enabled the development of various techniques to characterise common genetic traits, leading to significant progress in the field of gene-nutrient interactions.
This realisation has scientists and entrepreneurs racing to deliver more effective nutritional advice based on individual factors such as genetic makeup, gut bacteria, body type and chemical exposures. This may also shed light on the apparent injustice of why some people struggle with weight loss strategies whilst strictly adhering to what is deemed to be a healthy diet, whilst others can seemingly eat whatever they like without this reflecting on the scales.
Genotype-based nutrition has the potential to provide individuals at high risk of chronic diseases, such as diabetes, cardiovascular disease and cancer with customised nutritional advice to reduce disease risk and onset. There is convincing evidence that a broad range of variations in population gene expression exist, which may explain the unique differences in biological response to how we absorb and metabolise nutrients and, as such, predisposition to developing chronic diseases. Interactions between genotype and diet will become increasingly important when assessing disease risk and preventative management.
Cardiovascular disease and gene-nutrient interactions
Research shows that people’s cholesterol levels can respond very differently to dietary intervention methods depending on their genetic makeup.
Apoliprotein E (ApoE) is a protein involved in lipid metabolism. Individuals possess one of three different forms of ApoE, depending on their genotype: ApoE2, ApoE3, or ApoE4. Those with ApoE4, representing approximately 15% of the population, are more likely to have higher concentrations of cholesterol. In fact, those individuals possessing an ApoE4 genotype who consume a diet low in saturated fat are more likely to respond favourably to this dietary intervention; they will exhibit observable reductions in cholesterol levels, despite their genetic predisposition. This signifies that consuming a heart-friendly diet may be more pertinent for those with an ApoE4 genotype compared to other ApoE types, where effects may be negligible. However, until these people can be identified, recommending a heart-healthy diet to everyone is imperative.
Furthermore, individuals expressing the Apoliprotein (ApoA1) genotype will exhibit a higher HDL (“good cholesterol”) level in response to increased intakes of polyunsaturated fatty acids (PUFAs), which are considered healthy fats. Contrastingly, the science shows that individuals with a differing genotype display positive impacts on HDL cholesterol levels by decreasing PUFA intake. As such, it can be inferred that it would make sense for some people to consume higher amounts of PUFAs than others, depending on genotype, to reduce cardiovascular disease risk.
Researchers have discovered several gene polymorphisms strongly associated with type 2 diabetes risk, which can be modified with diet. The research suggests that individuals, who have been profiled with a higher predisposition to diabetes, may modulate their risk by consuming a low glycaemic index diet (GI).
The “Personalised Nutrition Project” led by a team of Israeli researchers, suggests that individuals have very different blood sugar responses to the same food —with some showing large spikes even after consuming supposedly healthy choices—. During digestion, carbohydrates are broken down into glucose, which are then released into the bloodstream. After consuming a meal, it is normal to experience an increase in blood sugar levels, termed “post-prandial glucose response”. However, consistently high blood sugar blood levels in the long run can increase the risk of weight gain, and disorders such as type-2 diabetes, high blood pressure and heart disease.
The study followed a cohort of 800 healthy and pre-diabetic individuals, whereby data was collected round-the-clock, to measure the effect of food on blood sugar levels. Many exhibited stark differences in their response to foods with the same GI. Some of the volunteers, dubbed 'carb-sensitive', had a higher blood sugar reaction in response to the more carbs they ate. This was in direct contrast to the 'carb-insensitives' whose blood sugar could increase even on a low-carb meal. Many responded very differently to fat consumption, and interestingly, tomatoes pushed up blood glucose response in some individuals, despite containing relatively low carbohydrates. The researchers suggest that carefully tailoring diets to meet individuals' blood sugar tendencies could be the wave of the future.
More research is required as the interactions among genes, microbiome, diet, environment and lifestyle are infinitely complex. Moreover, the effects of gene variants on risk of a complex disease are often inconsistent. Thus, a more robust evidence-based approach is required to improve the predictive accuracy of personalised nutrition. The future does seem to hold the promise of personalised nutritional recommendations based on genetic data, which will help fine-tune the prevention of nutrition-associated diseases. However, we have yet to progress in this field due to the complex nature of genes in the relationship between diet and health outcome.
Age plays an important role in changing nutritional needs throughout a person’s lifespan. In fact, what constitutes a healthy, balanced diet will be subject to slight variations depending on differing stages of life. Nevertheless, the core principles will essentially remain the same; a balance of diverse, nutritious, wholesome foods are focal to helping us look, feel and perform at our best, and to have a deeper, long-lasting impact from a health perspective.
In your 20s and 30s
Healthy eating is not always on the top list of priorities when you are in your twenties. Research often reveals that 20-somethings consume a greater volume of fast food compared to other age ranges and often eat inadequate levels of fruit and vegetables. This is probably due to the fast-paced, frenetic lifestyle most career-oriented 20-somethings lead, where food becomes an after-thought to ensure survival in its most elementary sense, instead of viewing nourishment as being synonymous with health and wellbeing. Nevertheless, the twenties are an ideal time in life to establish a healthy foundation for the rest of one’s life.
Bone density accrual continues until the late twenties, which makes nutrition for bone health crucial to reduce the risk of developing osteoporosis later in life.
Skipping breakfast and the over-reliance on quick, convenience foods containing elevated levels of macronutrients may result in an inadequate nutritional status and weight complications. In the long run, these set of circumstances create the perfect storm for increasing the risk of developing chronic conditions such as heart disease, diabetes, cancer and high blood pressure, all representing the major causes of death in modern day society.
Women who are considering starting a family should ensure they are consuming sufficient levels of energy, folic acid and minerals such as iron and calcium.
Making Health and Nutrition a Priority
Calcium: to ensure you are meeting the required calcium levels for health, consume three servings from the dairy group each day. Calcium-rich plant sources such as broccoli, spinach, beans and dairy alternatives are also good options.
Fibre: is an important part of a healthy balanced diet. Fibre can help prevent the onset of chronic diseases and can do wonders for your digestive health. Opt for wholegrain bread, experiment with porridge oats at breakfast and discover whole grains such as brown rice, bulgur and quinoa. Whole grains will also deliver the all-important B-vitamins, which help to convert food into energy, allowing you to stay energised throughout the day.
Fruit and Vegetables: ensure you meet your 5-a-day fruit and vegetable target. This will also contribute to fibre intake and boost your nutritional intake.
In your 40s
In the 40s many take their good health for granted, whereby healthy eating and exercise are often neglected. However, as we advance in age, good nutrition and reversing the sedentary lifestyle trend begin to gain some ground in our list of priorities. A diet rich in antioxidants will promote cellular stability, staving off the ageing process and helping to protect against diseases such as Alzheimer’s and certain types of cancer.
The metabolic rate, essentially the rate at which the body burns calories, will drop. However, the drop is minimal; the real reason why many people in this age bracket start to suffer from weight issues is due to the lack of movement. Excess weight, especially around the ‘middle’ is correlated with heart disease and diabetes. So start exercising and make a conscious effort to keep fit and be healthy.
A percentage of women in the 40s age range have low iron stores. Keeping the body well supplied with iron provides vitality, helps the immune system to function optimally and keeps the mind alert.
What to eat?
Antioxidants – a diverse range of differing coloured fruit and vegetables should be on the menu as they are an excellent source of antioxidants.
Iron – lean red meat is one of the most easily absorbed forms of iron. Aim to consume red meat 1-2 times a week. Fortified cereals can be a good option along with lentils, beans, pulses, and plenty of green, leafy vegetables such as spinach, green beans and broccoli.
In your 50s
Health problems, such as raised cholesterol, high blood pressure and type 2 diabetes are on the rise in this age group. As such, a low fat diet incorporating plenty of fruit and vegetables is the best way to counteract these conditions.
Moreover, the menopause will have a significant impact on this category of women. Symptoms will vary greatly and are linked to a decline in oestrogen levels featured in the menopause. This accelerates the loss of calcium from the bone increasing the risk of osteoporosis and brittle bones.
What to eat:
Calcium: consume 3 portions of low-fat, low-sugar calcium rich foods every day to minimise bone loss. The Mediterranean diet comprises lots of fresh fruits and vegetables, delivering a spectrum of heart friendly vitamins and minerals.
Watch the fat: as we age, the body’s energy requirement decreases. Body fat gets deposited when too many calories are consumed and insufficient levels are burned. Include monounsaturated and polyunsaturated fats from nuts, seeds and their oils instead of saturated fat.
Omega-3 fats: aim to eat 2-3 portions of omega-3 rich foods a week as these can help and keep bones and heart healthy due to their potent anti-inflammatory effects.
Hydration: continue to drink a couple of litres of water every day. Moderate caffeine consumption as it can interfere with the amount of calcium absorbed.
Spices: other anti-inflammatory spices such as cinnamon, turmeric and ginger confer many anti-inflammatory health benefits.
How to Eat Smart and be in Control whilst Eating Out
Making healthy choices when eating out often poses a challenge. It all seems to boil down to one dilemma: how can you ensure complete control over your diet when you are not in control of your eating environment?
You can be up against many villains when you are trying to upkeep healthy eating habits in a restaurant – big portions, too much salt, fat or sugar, tempting starters, side dishes and desserts just to name a few.
Sometimes you may have to deal with the added pressure of friends and family who may push you towards certain food choices, by encouraging you to live in the movement. In such instances, it is best to be prepared for this scenario and practice being strong by simply saying no, politely but firmly.
Is it possible to eat well when dining out? As with all challenges, it is best to be well prepared and informed. Eating at a restaurant does not necessarily have to sabotage a healthy eating regime. Implement smart-food strategies: plan ahead of time, consider the menu carefully and become menu savvy to ensure you select meals that will not lead you astray. Below you will find some tips to help you to feel in control of your eating out experience, and to help guide you in selecting healthier eating options.
Managing your portions
Keep it small: portion sizes at fast food joints or restaurants are usually much larger than what you would normally eat at home. Ask for half portions, share a large meal with a friend, and do not feel obliged to finish what is on your plate; ask for a doggy bag and take home the remainders of your meal.
Sharing is caring: share a starter if it strikes your fancy. If you are still feeling hungry after your meal, conclude with a fruit dessert or sip on a plain cappuccino. If you love rich desserts, order one and ask for additional spoons to split with your friends!
Appetisers: say no to bread or other nibbles before your meal arrives, as these are likely to increase your overall calorie intake.
Avoid super-sizing: choose standard or smaller portion sizes, and avoid "large" or "super-size" versions as they contain a high amount of fat and calories.
Making healthier choices
Be menu savvy when ordering: balance your meal by including healthier selections from all the different food groups such as lean meats, low-fat dairy, fruits, vegetables and whole grains. As a rule of thumb, half of your plate should be composed of vegetables, ¼ protein and ¼ (whole) grains.
Ask for more vegetables: if your meal does not come with vegetables, order sides of leafy green salad or steamed vegetables. This can replace a starter.
Opt for whole grains: look for dishes made with whole grains such as quinoa, brown rice, barley, bulgur or oats. Fibre keeps you fuller for longer and helps to maintain a healthy digestive system.
Tomato and vegetable-based sauces: if you need to pay attention to your weight, opt for tomato or vegetable-based sauces and soups rather than cream, coconut or cheese-based ones.
Keep salt in check: choose fewer foods that have been smoked or made with soy sauce or teriyaki sauce. Look for "light" versions of these sauces and ask for them to be served on the side. Do not add additional salt to your dish; exchange salt for peppers, other spices, herbs and lemon.
Ask for sauces on the side: sauces, condiments, dressings and spreads can supply excessive amounts of fat and salt to your meal. Ask for these on the side and so you can control how much you consume. Keep sauces to a minimum, and use just enough to deliver some flavour.
Skip sweet drinks: drink water in place of sweetened drinks such as soft drinks, ice tea or lemonade. Try sparkling water with lemon or lime slices. If you drink alcohol, limit it to one or two drinks for the day.
Learning the lingo: knowing menu terms and cooking basics makes ordering easier. Ask the food was prepared. Order foods that have been steamed, baked, grilled, or roasted. Fat and calories add up quickly when food is fried, deep-fried or breaded. Also watch out for sautéed items or foods described as "crispy," "rich" or "au gratin." Choose plain boiled rice instead of fried and go for boiled or jacket potatoes rather than chips or wedges.
Prepare in advance: examine the restaurant's website ahead of time. Look for healthier options that are higher in protein, fibre and vitamins and lower in calories, fat, sugar and salt. Ensure you eat a light dinner if you consumed a heavy lunch that day. Or, if you know ahead of time that you are going to a restaurant, cut back on calories during other meals during the day.
Eat slowly: it takes about 20 minutes for your brain to get the message from your stomach that you are no longer hungry. Fast eaters often are overeaters, while slow eaters tend to eat less, while still being satisfied. Wait until you have eaten your main course before you order a pudding. When you have finished the main course, you may discover that you are satisfied.
Pause during meals and put your knife and fork down between each mouthful. Taste and savour each mouthful of your meal – enjoy the experience.
Practice refusing offers to overeat: learn to say ‘no thank you’ politely but firmly
Restaurants may be intimidating to people trying to stick to a healthy diet, but with a little preparation and confidence, you can enjoy your restaurant meal without abandoning healthy eating by implementing some smart eating strategies.
Sophie Bruno is a Registered Dietitian living and working in Brussels (Belgium). Read Sophie's foodie blog which will enable you to learn, increase your knowledge & cultivate yourself in the field of nutrition & health directly from Brussels