We put 10 of the most common nutrition questions to Prof Grant Schofield and Dr Caryn Zinn. Here’s question 6: Do calories matter?
Is counting calories important for weight loss?
Great question. And we can answer it in several ways. According to the low-carb community, to achieve weight loss, you don’t need to worry about calories, you don’t need to count calories, you just need to make sure your carbs are kept low so your insulin is dropped, your hunger-fullness hormones self-regulate and you manage to lose weight. And that’s true for the most part. But calories actually do count because when you are that low-carb person, let’s say, if you overeat the amount of energy that your body needs to process for various functions, those calories don’t magically disappear. They’ve got to go somewhere. So if you overeat calories, then you won’t lose weight. So I think both arguments are right. You definitely need to watch your carbs if you’re on a low-carb diet and get your insulin low. But I think you cannot discount calories. They are important.
Here’s a thought experiment – every half an hour, I’m going to chop off another a hundred grams of butter and force you to eat it.
But under those conditions, under that thought experiment, you wouldn’t enjoy that. You’d be wanting not to eat that, but because of the several thousand calories here that energy would have to go somewhere and it could be stored as fat.
Or, you could eat something a little more delicious, such as macadamia nuts, the highest fat nut. They’re high in calories, and I can over-eat my daily calorie intake in five minutes. Willingly.
And there’s a more complex thing here – the calories-in and calories-out argument about weight loss and weight gain is true at one level, but it assumes that would be true in an open-loop system where the outputs don’t feed back and the inputs don’t feed back in a more complex biological system that involves neurons and microbes and hormones.
Of course the human body is a complex biological system with multiple feedback systems. And part of the problem is in diet, it becomes dysregulated and some of those main culprits, too much insulin, blocking of the hormone leptin, and high blood sugars and high blood insulin influence that. So at one level, counting calories and knowing what those are is important – at a practical level, counting every calorie is ridiculous.
It shouldn’t be what drives you. But of course people don’t eat for fuel only. We eat for so many different reasons. We eat when we’re happy, sad, depressed, frustrated – endless. And that’s when you lose control about how many calories you take in.
Prof Grant Schofield and Dr Caryn Zinn are the lead instructors in the Certificate of Advanced Nutrition.