I have a question for you: When we discuss nutrition, which word invariably crops up more than any other? Answer: Most probably it’s “calories”.
Purpose Of This blog
The purpose of this blog is to chronicle what calories are, and to understand the role calories play in your nutritional needs – with the anticipation that you will be encouraged to eat healthier, and make educated decisions about your diet. Learning the basics of macronutrients and the number of calories they provide can help you create well-balanced meals.
What Are Calories?
In dietary terms, calories are the amount of energy that a food provides, and the energy we use in physical activity. Just as the fuel burned by a car provides energy, the calories in food is the fuel burned by our bodies to provide energy.
The required intake of calories depends on several factors, all related to our body needs, which are impacted by our overall general health, physical activity demands, weight, height, body composition, age, and gender. If we consistently take in more energy than we need, we will gain weight. If we take in too little energy, we will lose weight, fat, and eventually muscle weight. The type and amount of food we eat determines how many calories we consume. For many people on a weight-loss diet, the number of calories in a food is a deciding factor in choosing whether or not to eat it. I am not on such a programme, but I invariably check the number of calories on food labels, so that I can choose the healthiest options for packaged food.
Number Of Calories Required
As we age, we generally need less calories to maintain our bodies as our metabolism slows down. One source claims that on average men need 2,500 calories daily and women 2,000 (www.nhs.uk). However, a plethora of assertions have been posited documenting how many daily calories we need. Calories are essential for human health – the key is consuming the correct amount.
All calories are created equal, but their nutritional value can be different. The exact same amount of calories from two different types of food can pose completely different biological effects in the body, because we don’t eat calories, we eat food and some foods have a lot more nutritional value for the same amount of calories. A 450-calorie meal of fruits and vegetables has more health benefits and will keep you feeling fuller longer compared to a 450 calorie snack of a Starbuck’s Frappuccino. Keeping calorie intake within certain limits will not necessarily ensure a healthful diet, as different foods have different effects on the body. But this is the subject of a blog in itself.
Empty calories are those that provide energy but very little nutritional value, containing virtually no dietary fibre, amino acids, antioxidants, dietary minerals or vitamins. Empty calories come mainly from solid fats and added sugars; both are claimed to make food and beverages more enjoyable. However, they add many calories.
In a lively, instructive and animated video, Emma Bryce (on YouTube) presents a detailed and instructive analysis of the role of calories, “What is a calorie?”