It riles me a bit when people reduce nutrition down to calories in v calories out.  

Firstly because the calorie content of a particular food is calculated by burning a sample of it in an oxygen-filled chamber and seeing how much the resulting heat warms water, which is great because this is exactly what our bodies do with food.  Wait, no it isn't….

Different foods cause different reactions in our bodies - they raise and lower different hormones to different levels - which in turn changes how we respond to daily life - some nutrients are used by our bodies as fuel, some are used to repair muscles, some are used to extract vitamins from other foods some are treated by our bodies as poison. Nutrients do different jobs in our bodies that cannot be simply equated to how much they heat water when they are burnt in a repeatable environment.  Each body on this planet is a unique environment, subject to myriad different factors such as genetics, pollution, stress, age, height, mood, activity levels, etc so to reduce nutrition simply to calories is meaningless.

Having said that, if all you care about is your weight and how much body fat you have, eating more than you use will definitely result in you getting fatter.  But to use this information to suggest that it doesn't matter what you eat, it just matters what the calorie content is, is dangerous advice.

Secondly, if you get all your daily calories from sweets, crisps, cakes and fizzy drinks, you CANNOT tell me that someone eating the same calories from meat, fish, eggs, fruit, vegetables, nuts and seeds is not healthier.  You know they will have a clearer mind, clearer skin, a healthier heart, a more positive attitude.  By the calories in v calories out argument, you could get all your daily requirements from alcohol with zero vitamins, minerals or nutrients. You would die

Calories in v calories out has a very limited use.  It is much better to think about the quality of those calories, the colour of those calories and usefulness of those calories.  That doesn’t mean you can’t have the odd croissant or doughnut, it just means if you have them every single day, just as if you drink alcohol every single day, you might have a problem.

My last word on this is that being able to afford to eat healthy food is a luxury.  It really is, which is a disgrace in the 21st century. So if you are in a position to choose between a £1.50 pizza for dinner and oak smoked salmon jus with toasted quinoa and a feta and marrow-bone drizzle, don’t fucking squander that priveledge!