There's a lot of conflicting information about what constitutes a healthy diet. That's why the most important thing is to be mindful of how what you eat makes you feel. Eating a piece of cake might be great at first. You're celebrating a birthday, it's sweet and delicious and you get that sugar high. But then comes the crash. You feel tired, cranky and bloated for the next couple of hours, and you crave more sweet food to do it all again. Next time ask yourself, is the cost worth it?
Similarly, eating something healthy (and healthy definitely doesn't mean boring and tasteless) makes your body feel good - you have steady, lasting energy and your brain feels sharp. Some foods such as kefir (a fermented milk drink) and bone broth can actually make your whole body tingle with health. I'm not kidding - I've felt it and others have too.
The next clue is to look at what our ancestors were eating before diabetes, heart disease and neurological disorders came along. Chances are you'll find clues to what will work for your body. Humans can live and thrive on all many different diets: high in carbohydrates (assuming you're also physically active), high in fat and protein, existing almost solely on animals or eating strictly vegetarian. What our ancestors weren't eating was processed foods that contained sugar, preservatives, or pesticides. They ate fresh food that was in season. Some things they ate raw, some things they cooked. Some things they soaked or prepared with fermentation.
So what can science tell us about nutrition? Bear with me here, there's a lot to cover. Hopefully you've heard about most of it already, but if not, there are plenty of resources on the internet to dig deeper into each topic.
Sugar is toxic to the body
If you haven't already heard, refined sugar is toxic to the body, and highly addictive. It spikes blood sugar levels, causing a massive influx of insulin. This in turn signals the body to shuttle sugar and fat into our muscles if we've been exercising, or to shuttle them into our fat cells if not. This insulin spike means our cells become less sensitive to insulin's signalling, so each successive blood sugar spike requires more insulin, leading to type 2 diabetes. Once the insulin does its job, blood sugar levels crash making us hungry for – you guessed it - more sugar. Sugar is also highly inflammatory to the body, contributing to many health problems. Sugar containing foods such as fruit are fine in moderation, especially if paired with exercise, but in general, ditch the refined sugars.
Eat lots of healthy fats
Fats, especially saturated fats, have now been shown to be healthy and vital to life. In fact, the membranes of our cells are comprised of at least 50 per cent saturated fats, and our brains are mostly saturated fat! You can see now why fat is an essential macronutrient! A diet high in healthy fats typically raises good cholesterol (HDL or High Density Lipoproteins), while simultaneously lowering bad cholesterol (small particle Low Density Lipoproteins). Fats aid cognition and help with immunity (think fat soluble vitamins) and hormone balance (without cholesterol, your body can't produce testosterone).
Consume healthy fats such as olives and olive oil, fish, avocado, coconut oil, eggs, meat and chicken (no need to avoid the fatty cuts), nuts and seeds. Trans fats such as those found in fast foods and Margarine should be eliminated.
Eat a moderate amount of protein
Apart from fat, protein is the only other essential macronutrient. The amount of protein we need typically isn't that high, and would require one or maybe two servings of protein (meat, fish, eggs, seeds etc) a day. This range is typically somewhere between 70 and 200 grams of protein a day, depending on bodyweight and activity levels. Those recuperating from illness should eat a little more protein as their body will require additional amino acids to repair itself. As we age, our protein absorption does degrade somewhat, so the elderly should eat a little more protein.
Eat lots of in season vegetables
Just like our mothers used to say – eat your veggies! Eat a variety of colourful vegetables that are in season. They are full of vitamins, nutrients and antioxidants. They also are high in fibre and keep you feeling full.
Reduce high glycemic index carbohydrates
Be mindful of your consumption of fruit and refined rice and grains, especially if you are not very active. When overeaten, they can spike your blood sugar levels and lead to the same problems as sugar consumption. Good choices of fruit are berries as they are low GI and high in nutrients. Look at eating brown or black rice instead, as long as it's been soaked or fermented (covered below).
Limit foods that cause inflammation
Many people's bodies respond with inflammation and bloating when a significant amount of gluten is consumed. Similarly, some people don't digest dairy well and find mucus production is much higher when consumed, however fermented dairy is often tolerated better. Experiment with limiting these foods to see what effect they have on you, or get in touch with a dietician for more in depth help.
Consume some foods raw
When foods are cooked, it makes them easier for our bodies to digest. Some things like potatoes require cooking, but doing so also reduces the nutrient content and destroys the enzymes present in the food. Eating some raw vegetables, such as a salad, means your body will still obtain the enzymes it requires from food. Salads will also keep you feeling fuller longer as the body takes more time - and energy - to digest them.
Eat fermented foods
Our guts are home to billions of bacteria. These bacteria break down food for us and release neurotransmitters such as serotonin (it's estimated that as much as 90 per cent of it is produced in the gut!), dopamine, butyrate, BDNF (brain-derived neurotrophic factor) and GABA (gamma aminobutyric acid). A healthy diet includes fermented foods to create a diverse gut biome – eat sauerkraut, kefir, yoghurt (if you tolerate dairy), kim chi and miso. Also of note is sourdough bread (the yeast fermentation largely reduces the gluten content and lowers the GI of the bread) and wine and beer (these have some health benefits in moderation due to the fermentation process).
Limit pesticides and anti-nutrients
Residues of pesticides are found in some fruits and vegetables, especially the "dirty dozen" - those with the highest levels of pesticides. On the other side are the "clean 15" – those with the lowest level of pesticides which are thought to be safe even when not organic. When animals have been fed hormones, any meat and fat that is then consumed will contain some of these hormones. Animals should be fed their natural diets, rather than fed grains or soy, and be allowed to roam free.
Anti-nutrients such as Phytic Acid can be found in high levels in grains, legumes, unhulled rice, nuts and seeds. Anti-nutrients interfere with the absorption of minerals such as phosphorus, calcium, copper, iron, magnesium and zinc. Thankfully they can be drastically reduced by soaking, activating (soaking in salty water and drying), sprouting, or lactobacillus fermentation. Specific information is easily available on the web.