By Nicola Howard & Sarah Bengochea
Are you counting calories?
Every packet/tin/tub in a supermarket or food shop is shouting at you how many calories it contains either as part of the traffic light system or as a marketing ploy.
Why do we need to know? Is it that calorie counting helps us to be healthier? Or are we missing the point when it comes to understanding the delicate and complex relationship between food, nourishment and our health?
In this article, we explore the purpose of calories and also question whether – the singular focus on calories as a way to determine food value could be detrimental to our health?
Focussing on just calories misses the point that real food is all about food, health and nourishment. Here at Weight in Mind, we guide you towards a more straightforward, more delicious approach to food, eating, health, weight management, and just feeling good. So in the words of Giles Yeo, the obesity researcher from Cambridge University, calories don’t count.
What are calories?
In the late 19th century, a chemist called Walter Atwater calculated the energy content of different foods by determining how much heat energy was released when different foods were incinerated. He then monitored the amount of energy lost through undigested foods. His calculations then determined that protein and carbohydrates produced on average 4kcal per gram and fat on average 9kcal per gram. These calculations were used to determine the calorific value of foods.1
Why have calories become important?
Due to the great depression and various wars, governments needed to estimate the number of calories and specific vitamins and minerals required to avoid malnutrition within their military forces and the general population. Later, when higher-income countries became concerned about obesity and non-communicable diseases such as heart disease, calories were used as a guide to educate populations. Nutritional guidelines advocate the ideal daily calorie intake for men and women, but these are based on population averages.
Should calories have become the focus?
As we have seen, calories became the focus to simplify the message to help manage the health and weight of populations. But calories do not explain why we eat food.
Food contains multiple nutrients, minerals, and bioactives such as phytonutrients, food structures and other factors which combine as part of the human diet and influence our health. As science develops, we are beginning to understand that we are a complex ecosystem that interacts with the food we consume as humans. The simplistic message of counting calories, despite its good intention, misses the point when it comes to human health.
Not all calories are equal.
The calorie content of food is calculated based on the general factors of fat, protein and carbohydrate developed by Walter Atwood and is applied indiscriminately to all types of food. But the actual energy extracted depends on the cellular structure of the food, the processing methods used to make the food and the meal composition.2
Processed food v unprocessed food.
Food processing changes the structure and composition of foods and affects how they are digested. If we looked at caloric content alone, 100g of chocolate-coated cookies has 13% fewer calories than 100g of almonds. Due to the processed nature of the ingredients in the cookies, very little cell structure remains and most if not all the calories within the cookie are available for absorption. However, in unprocessed almonds, even when chewed, some of the fat content remains locked within the cell structure, meaning that the actual calorie content of the almonds is much lower.2
Nutritionists over the years, such as Geoffrey Livesey, have campaigned to have labelling changed to reflect caloric availability, but this was rejected by a UN Food and Agriculture Committee in 2002, and Giles Yeo has recently tried to restart the debate.3
No two people are the same.
Research has observed that even identical twins vary in their response to identical meals.5 How each person digests a meal depends on the differences in an individual’s gut microbiome more than a meal’s macronutrient content (such as fat or protein).5
A healthy gut microbiome increasingly is linked to general health and wellbeing.6
Not just the gut microbiome.
The identical twin study also highlighted that meal composition (high fat / high protein v’s low fat / low protein), the context of a meal (when we ate), how much exercise we did, sleep quality, circadian rhythm were all key factors determining how our food is metabolised.
We eat food, not calories.
Food is not just energy or caloric content but “a complicated mix of nutrients, minerals, bioactives, food structures and other factors”4 such as fibre, polyphenols, probiotics, and prebiotics, which all affect our health. The use of calories or traffic lights on that packet/ tin/ tub in the supermarket or food store diverts us from the food itself. As our lives get busier, we rely more and more on these labels and the food industry to provide the food we eat.
We need to stop counting calories or relying on food traffic lights and focus on eating natural foods which are as unprocessed as possible.
The type of food, not the total calories, determines if we are healthy.
The identical twin study highlighted that food quality, food source, and food type are essential for overall health and the gut microbiome.6
Food quality. Always choose unprocessed or the least processed food over highly processed food.
Food source. The more diverse our diet and the more types of plants we consume, the more varied our gut microbiome will be. The health of the gut microbiome links to our general health outcomes. The more local the food source is, the fresher it is likely to be. Trying to eat food when it is in season ensures that it is more likely to be local and more likely to be better for the planet and higher in nutrition. In a study looking at the Vitamin C content of broccoli, when grown in the Autumn (its natural season), it had a higher Vitamin C content than when grown in Spring.
Food type. Not all plant foods are healthy. Fruit juice, refined grains and sweetened drinks may be plant-based but are less nutritious than less processed foods such as broccoli, tomatoes and seeds.
The food industry has seen the growth of the plant food market and uses green labels, pretty pictures of vegetables and plant-based health statements to market their products. But be wary as these are still processed foods, and processing changes the structure and nutrient content of the ingredients, as highlighted before.
Change the conversation.
Perhaps we need to stop asking how many calories a food contains or how many calories I should eat and look at the food we consume. As we have seen, the value of foods is much more significant and complex than the calorie; perhaps the author and journalist Michael Pollan has the right approach in his often-quoted words, “Eat food. Not too much. Mostly plants”.
Here at Weight In Mind, we want people to feel confident about their food, how food influences their health, and feel inspired and capable in the kitchen. If this sounds interesting and good for you, you may like to attend one of our online health courses either on a 1-2-1 basis or as part of a group.