Most experts agree that weight loss, maintenance or gain is a matter of caloric balance: that is, your energy needs versus your energy intake.
Your energy needs are calculated from a combination of your basal metabolic rate (BMR), your non-exercise activity thermogenesis (NEAT), and any exercise you do.
It’s impossible to get exact numbers for your individual calorie burn, which will be different every single day depending on your activity levels, movement, stress levels, metabolic stress, how well you sleep, your waking hours, and even tiny details like how much you fidget, sit or stand. But you can get a decent idea by using a trusted formula like the Mifflin – St Jeor formula.
On the flipside is your caloric intake, which comes from the food and drinks you consume. This is relatively easy to calculate, by using a spreadsheet or app, or keeping a rough tally using a calorie guide or the caloric information on food labels.
Just bear in mind that no numbers are completely accurate, with some food labelling information believed to be over 10% out. The take-home point is that it is impossible to know exactly how many calories your body needs, or how many calories you have ingested.
That’s why it is a good idea to get in tune with your body’s hunger and satiety signals rather than eating by the clock or from a rigid plan.
Food is made up of macronutrients: proteins, carbohydrates and fats. All foods contain one or more of these. For instance, chicken breast is mostly protein with a small amount of fat. Potatoes are mainly carbohydrate with a minuscule amount of fats and protein.
Oats are mostly carbs, with some fat and a small amount of protein. Each macronutrient carries a caloric load: 1gram of protein is 4 calories, 1gram of carbohydrate is 4 calories, 1gram of fat is 9 calories.
Unless you are designing a specific meal plan to get super-shredded for the bodybuilding stage, or to put on as much weight as possible in a short amount of time, don’t sweat the minutiae.
What’s more important is getting a good balance of macronutrients at every meal, eating enough protein (most people don’t, and protein is essential for almost every function in the body), paying attention to healthy fats (from oily fish in particular), and neither overshooting not failing to meet your caloric needs by too much on a consistent basis.
If you only do these 5 things, you’ll be well on your way to eating a healthy diet which will nourish your body and protect your health.