ANSWER: Should a food be judged by its key macronutrient? Dietary fat was unpopular for decades before research revealed the widely varying health effects of different fats – some good, others not so good. Nowadays, the dietary witch-hunt has turned to carbohydrates. But before you eschew your breakfast oats, let’s look at the evidence: what are carbohydrates? And are oats good or bad for us?
Carbs are one of three macronutrients found in food (along with protein and fat) that provide fuel for our body. They consist of building blocks called saccharides, or sugars, joined together, just as protein consists of amino acids bonded together.
The simplest forms are single units of sugar, such as fructose in fruit, and two saccharide units bonded together, such as sucrose, which is made up of glucose and fructose. Sucrose is found in small amounts in many plants, but table sugar is the sucrose sourced from sugar cane and sugar beets. Table sugar is added to many processed products, including ice cream, biscuits, tomato sauce and bread.
When many saccharide units are bonded together, they’re called polysaccharides. These are found in typical carbohydrate foods, such as pasta, bread and potatoes; in nutrient-rich foods, such as fruit, vegetables, nuts, seeds, grains and legumes; and in nutrient-poor processed foods, such as potato chips. In other words, the presence of polysaccharides doesn’t imply nutritious content.
When we eat carbohydrates, they’re typically digested and broken down into sugar units that are absorbed into our circulation. The rate at which this happens depends on the food – the free sugars in fruit juice are absorbed more quickly than the sugars in a whole piece of fresh fruit, for example, as it must first be mechanically and chemically digested before the sugars are released and absorbed into the body.
But not all carbohydrates are digested. Although dietary fibre is a polysaccharide, it is resistant to digestion and absorption in the gut. Instead, it helps our gut by promoting bowel movements and the growth of beneficial gut bacteria. Foods rich in dietary fibre include oats, nuts, beans, lentils, fruit, vegetables, brown rice and other wholegrains such as whole wheat.
By eating more fibre-rich whole foods, we may lessen the risk of obesity, diabetes, certain cancers and cardiovascular disease. Dietary fibre is thought to reduce cardiovascular-disease risk through its ability to lower blood-cholesterol levels, an effect that’s particularly strong with the beta-glucan fibre found in oats and barley.
So, back to your breakfast: oats, fruit juice and yogurt. A healthy diet is largely based on eating wholefoods and fewer processed foods, especially those containing high levels of sugar, saturated fat and salt. Oats are a nutritious option, as is yogurt. But to improve your breakfast, swap the fruit juice – high in free sugars – for a whole piece of fruit. Try an overnight oat recipe made with real fruit, oats and yogurt (or milk). It’s more nutritious and you will still get to enjoy a delicious oaty start to your day.
- Combine ½ cup of rolled oats with ½ cup of milk or yogurt, then add the following ingredients and refrigerate overnight:
Peanut butter banana
- 1 mashed banana
- 2 tbsp unsalted peanut butter
- top with sliced banana and chopped peanuts
- 1 apple, diced or grated
- 1 tbsp honey
- 1 tsp cinnamon
- top with pumpkin seeds
- ½ cup mixed berries
- ½ teaspoon vanilla extract
- top with chopped nuts
- 1 small carrot, grated
- ½ banana, mashed
- top with pecans and raisins
This article was first published in the September 9, 2017 issue of the New Zealand Listener.