It should be pretty simple: maintaining a healthy weight means consuming just enough calories to support our body’s needs, right?
In reality though, it isn’t always that straightforward – well, not for everybody, because as we know, humans aren’t a ‘one-size-fits-all’ species. We come in different shapes and sizes, our lifestyles, diets and health can vary, as can the way we store fat (some people are naturally prone to carrying fat on their tummies, for instance, and then there are those lanky lads that seem unable to gain weight no matter how much they eat).
According to guidelines, our age can effect our calorie requirements too – which UCLA statistician Nathan Yau illustrated with a graph this week, published on his Flowing Data blog (flowingdata.com).
Yau plotted out the amounts advised for different age groups depending on their lifestyles (active, moderate or sedentary), using the recommendations issued by the US Department of Health and Human Services, and then compared them with the average amounts people in those categories actually say the consume, using figures from the 2009 -12 National Health and Nutrition Examination Survey.
Overall, the graph illustrated that people with sedentary lifestyles tend to consume too many calories, while those classed as having active lifestyles often fell short of eating the recommended amounts.
Here are the figures according to the graph…
For women with sedentary lifestyles:
Age 5 - 10: around 1,400 calories a day
Age 20 - 25: around 2,000 calories a day
Age 25 - 50: around 1,800 calories a day
Age 50 - 80: around 1,600 calories a day
Those with moderate activity levels can eat an additional 200 calories a day, increasing to 400 a day for an active lifestyle.
For men with sedentary lifestyles:
Age 5 - 10: around 1,400 calories a day
Age 20 - 40: around 2,400 calories a day
Age 40 - 60: around 2,200 calories a day
Men can also add an additional 200 calories a day for moderate activity levels and an extra 400-600 if they are class themselves as active.
It’s now well established that being overweight is a major health concern, being linked with significantly increased risk of conditions including heart disease, stroke, Type 2 diabetes and certain cancers. But while having an idea of our calorie-intake – and keeping our weight in check - might be useful, when it comes to nutrition and being healthy, these figures are only part of the picture.
Also, guidelines are just that – a guide designed to suit the ‘average’ person, so it’s important that individual factors are taken into consideration too.
Am I moderate, active or none of the above?
Rating our activity levels can be tricky too. For instance, a person who goes running four times a week – but works in an office sitting at a desk for eight hours a day, might end up being equally as active as somebody with a more physical job who walks to work, but does very little formal exercise.
"Although guidelines for calorie intake can be a good place to start, they should definitely be used with caution. Calorie needs will depend upon a whole range of factors and therefore individual requirements can differ greatly, even for people of same age/gender,” notes Charlotte Kennedy, a sports nutritionist at Etixx.
Tailoring our diets
Our activity levels can vary from day to day, or week to week, as well, so it can be useful to have a flexible approach (but the good thing is, if you are generally active on a regular basis, the occasional treat won’t do too much harm!).
“If you’re sedentary for most of the day at work, your calorie requirements will be much lower than someone who has an active job. Similarly, if you do any exercise, this will increase daily energy needs and you will need to eat more to maintain weight,” adds Kennedy.
Muscle vs fat
The reason those Body Mass Index (BMI) charts can be controversial is they only consider a person’s age, but don’t take into account different body types.
Of course a 6ft teenager is going to weigh more than a 5ft teenager! Again, this doesn’t mean the guidelines should be dismissed entirely, but we all need to make room for common sense. “It’s also important to remember that muscle uses more energy to maintain than fat, therefore the more muscle you have, the higher your calorie intake needs to be,” states Kennedy.
Also, being a ‘healthy’ weight does not always mean a person is healthy on the inside – sometimes a poor diet and lifestyle might not lead to weight gain, but could still be contributing to things like high cholesterol and fatty deposits and inflammation around the organs.
Calories are not all created equal
Finally, counting calories is not the be-all-and-end-all of a healthy diet. In order to eat well for optimum health, we need to be thinking about balance and nutrition too.
An avocado, for instance, might be more calorific than that biscuit, but it’s packed full of heart and brain-boosting omega-3, while the biscuit is nothing but a quick sugar hit. Nutritionists and dieticians talk about ‘empty’ calories – foods that might seem ‘good’ because they are ‘low fat’ or ‘low cal’, but which contribute very little nutrition. As always, it’s all about the balance.