Every time I go on a diet (sorry, make a lifestyle change..) I rely on My Fitness Pal (MFP) to keep me on course and make sure I’m not going mental with my eating and calorie intake. I do, however, struggle with the preset numbers, goals and percentages, and also never know whether to eat back the calories I’ve burned during exercise, or, wait, does that negate all my hard work?!

There are conflicting opinions all over the internet, which is why I’m still not sure what to do. The default ‘activity’ levels on MFP don’t really match up to real life events, and the difference between ‘lightly active’ and ‘very active’ are quite subjective. I walk home from work 5x a week, which some may say makes me active, however, someone who goes hard and fast at the gym every night also falls into that same 5x a week category. We’d both need a very different amount of food each day though. The plot (and hopefully not my waist) thickens..

I’ve also had trouble with calculating my TDEE online, with some sites giving you a number based on what you need to stay alive, and some with that minus what you need to lose weight already taken into account. And they also depend on the amount of exercise you do – but what if I have a lazy week followed by an active one, followed by a ‘lightly active’ one? Should I be resetting my calorie needs every seven days? How dull.

The formula I’ve found that works for me is to keep my calories constant, and only change my exercise. By that I mean, every day my calorie limit on MFP is around 1800. And that’s just food. Whatever number of calories I go over that amount and into the red, that’s what I need to burn off (or have already burned) at the gym or by running. That way, if I get home and just really can’t be bothered to work out, as long as I’m still in ‘green’ calories, I won’t gain weight. I’ve found that logging my exercise into the planner is confusing, as I can fall into the trap of overeating, or overestimating how much I’ve burned, leading me to get cocky with my calories. I’d much rather assume that a 30 minute run and 90 minutes at the gym are going to blitz any ‘red’ calories than painstakingly work out the time, speed and distance of my walk to the tube, or the effects of my un-loggable kettlebell exercises.

I’ve also found that planning my day’s food in advance helps to keep me in check and lets me know whether or not I need to go extra hard at the gym. From Monday to Friday my breakfast and lunches are always the same so they can be logged all at once, with post-work, pre-gym bites remaining fairly constant over those five days too. Any extra treats or biscuits I snaffle at work drop into the ‘snacks’ category, and are generally the only thing that sends me firing into negative calories on MFP.

Eat over my limit on workout days, eat at it on days off. Simple.