I know that nutrition is not simple. There are so many things to know and to remember. So if you're ever in doubt, remember to keep it simple. Avoid eating packaged foods. Stick to things that come from the earth and you will be fine.
When you're preparing food in the kitchen, you might wonder if there is a certain way to cook your food in order to make it as healthy as possible. The answer is yes. There are certain tricks. The point here is to think how the food will affect your body. So if we're talking about how carbohydrates will affect your blood sugar levels, you want to aim for the best way possible.
One example is the sweet potato. Boiling them is the best way to cook them as they will retain most of their antioxidants, compared to roasting or steaming. (Maybe make your Sunday roast more of a special, rather than regular occurrence?)
In terms of the science behind it, boiling is said to thin out the cell walls of the sweet potato and gelatinise the starch, which may enhance the bioavailability of nutrients. And talking about GI (or Glycaemic Index, the number that helps to know how foods affect our blood glucose levels), we can see that the glycaemic index of boiled sweet potatoes is half that of baking or roasting - which is very good news. So next time you're serving sweet potatoes, boil them. And remember that boiling or steaming doesn't require the addition of any fats or salts, and that is a plus.
Again, keeping it simple is a sure-fire pathway to good health. So, the next question. To peel or not to peel vegetables? The answer is simple, DO NOT peel anything. Most of the nutrients are in the peels or skin of vegetables. For example, the humble sweet potato skin has 10 times more nutrients than the flesh itself!
Next up, let's talk frying pans. What about deep frying, roasting and so on? First, let's get a bit more scientific here. Let me introduce you to Advanced Glycation End Products (AGEs). They exist in high levels in uncooked animal foods, but can also be generated by cooking food with dry heat at a high temperature. AGEs create many health problems, including inflammation, cataracts, Alzheimer's, heart disease and may accelerate diabetes.
Another term that you should know when roasting and pan frying is Polycyclic Aromatic Hydrocarbons (PAHs), found in meat, chicken and fish cooked with dry heat. PAHs are linked to an increased risk of cancers of the stomach, bowel, prostate and pancreas. Then there's acrylamide, found in carbohydrate-rich foods prepared at high temperature, it's been linked to an increased risk of cancer. In summary, try not to overdo the roasting and pan frying. Do it only once in a while.
So what about eating things raw? That is the best, to be honest! Heat can and will affect the structure of your foods. After raw, boiling and steaming are the healthiest cooking methods. Steaming is one of the cleanest ways to cook. It transfers more heat at the same temperature so the food cooks faster and fewer micronutrients and phytochemicals are lost. In addition no fat, oil or salt is needed. Just remember to do not over steam or boil anything. Just do it for a few minutes and this way it won't affect your food's nutritional value.
The only downside to boiling your food is that boiling for too long will result in water-soluble nutrients leaching into the water. Up to 60% of vitamin C, B1, B2 and B6 can be lost by boiling vegetables. The solution is to drink that water as soup, or to blend it with your vegetables to create sauces or even vegetable stock.
Now, for one last tip: Add lemon juice and vinegar to your meals; they lower the GI of your carbohydrates. How does this work? The acidity in your food slows down your stomach's digestion, which then slows the delivery of food to the small intestine. In summary it slows down how your body utilises the sugar from carbohydrates so you will feel less hungry later, and therefore won't be tempted to eat too much. Kombucha is a great way of doing that too, since Kombucha is a type of vinegar.