Jane McClenaghan: Nutrition is about much more than the sum of calories in food
RECENT news reports have been all over the idea that there should be a calorie count on menus in cafes, restaurants and your favourite takeaway in a bid to help control the obesity epidemic.
While I am all for helping people to make healthier choices, I am not entirely in agreement that calorie counting is a good idea.
:: Where do calories come from?
Let's take a step back to basics, just for a moment and remind ourselves where calories in our food come from. Protein, fat and carbohydrate are our macronutrients that provide us with energy (a calorie is a unit of energy).
Per gram, fat has the highest calorie count, so one gram of fat contains 9kcals compared to 4kcals per gram of protein and carbohydrate. So in theory, cutting back on fat will reduce our calorie intake and help us to lose weight. But in reality, calories are a little more complex than this simple equation would suggest.
Each of these macronutrients has a very different effect on our appetite and metabolism. Fat in our diet is not the same as the fat deposits we have around our muffin tops, bingo wings and flabby bits. The body will always use carbohydrate as its preferred energy source before it uses fat.
Carbohydrates give us a quick and efficient energy supply that is easy for the body to convert to glucose. Fat and protein have to go through a complicated process called gluconeogenesis before we can use them for energy, so they are less likely to end up as fat stores in our body.
:: Low fat and low calorie diet
While low-fat diets do work for weight loss in the short term, but long term they tend to be unsustainable and unhealthy. Fat is an essential nutrient. Just as important for our health as vitamins and minerals. A deficiency in the essential omega 3 and omega 6 fats can lead to an increase in cholesterol and inflammation and play havoc with our hormones, not to mention the effects on our mental health.
Fat also helps regulate our appetite as it induces satiety and helps regulate our hunger hormones leptin and ghrelin. Without fat in our diet it is difficult to feel sated, so we can end up with more cravings, and more fat storage.
If we cut fat out of our diet we are also at risk of becoming depleted in the fat soluble vitamins A, D, E and K.
:: How many calories?
Let's break it down. A 100kcal snack could be two ginger biscuits, or a small handful of Brazil nuts (about four nuts). One of these will spike our blood sugar levels, trigger a surge in insulin and result in fat storage and sugar cravings, with very little additional nutritional value. The other will help to curb our appetite, help regulate insulin and blood sugar balance and is packed with nutrients like selenium, vitamin E, protein and healthy fats. I know which one I would prefer.
Another example might be to compare a typical chocolate bar with a salmon fillet. Both of these contain about 250kcals. One makes you fat, one helps keep you healthy!
:: Eat real food
I live by the motto ‘eat real food'. Low-calorie food can be packed full of sweeteners and chemicals that are added to compensate for the lack of fat these foods contain. If the low-calorie menu catches on, I think it could be to the detriment of our health. Nutrition is about so much more than just the sum of calories in food. The number of calories is nowhere near as important as the source of the calories.
I think the push towards calories being listed on menus is a step towards poorer dietary choices, rather than better.