The fundamentals of nutrition – let’s get into it!
Nutrition can seem complicated, but the fundamentals are straightforward.
Prefer to watch than read? Then please check out the video below:
Food is fuel
Food is fuel – we need it to function, thrive, and stay alive. The quality and quantity of what we eat directly impacts our health, performance, and body composition. Manage both well, and you'll feel and look pretty damn good.
Calories
We’ll start by touching on calories. A calorie is simply a unit of measurement for energy. Calories don't tell you whether a food is good or bad – just how much energy it contains, but because energy intake determines whether you lose weight or gain it, it's the primary thing we need to manage when looking to improve body composition.
Food isn't just fuel
But food isn't just fuel – it's nutrients. We have macronutrients – protein, carbs, and fats – and micronutrients – vitamins and minerals.
Macros
Protein
Protein is the most important macronutrient, so we’ll start here. It’s the building blocks of organs, muscles, skin, and hormones and is essential for tissue repair and growth. Which means whether you want to build or maintain your muscle mass, protein is what you want to focus on. But how much do we need? Well, the current RDA is 0.8 g/kg/day, but that falls well short of optimal (Phillips et al., 2016). So, instead of aiming for that, we actually want to hit closer to 1.6 g/kg/day (Morton et al., 2017). So, an 80kg dude would aim for 128 grams per day. Protein intakes beyond this do have their place for some individuals, particularly if you’re super jacked, but most people will be maximising their gains at 1.6 g/kg/day. Per meal, aim for 0.3–0.4g/kg (~20–40 grams per meal), which will be enough protein, and specifically enough leucine, which is the trigger here, to get a spike in muscle protein synthesis (Schoenfeld & Aragon, 2018). When it comes to building muscle, if there’s anything you want to get right, it’s protein. In fact, if you get this right, you can’t go far wrong!
Carbohydrates
Carbohydrates are our body's primary energy source and are particularly important around training. Some diets restrict carbs, but keeping carbs at a reasonable level gives you food flexibility, supports satiety through volume, and provides fibre-rich foods that benefit gut and cardiovascular health. Carbs are also protein-sparing, meaning they help preserve muscle in a deficit.
Fat
Then we have fats, which are involved in many key functions, such as hormone production (including sex steroid hormones: testosterone, progesterone, and estrogen), nutrient absorption (vitamins A, D, E, and K), immune function, and cell structure. Moderating fat intake when looking to lose weight is always a consideration, as fats are the most calorie-dense macronutrient, but as shown in research, diets with 20% vs 40% fat have significantly lower concentrations of sex steroid hormones (Hämäläinen et al., 1984). I’d recommend being around the middle of this range, as the bottom end is evidently suboptimal for hormones, and the top end means a large share of our calories will come from the most calorie-dense macronutrient, which would drastically reduce food volume – not ideal for satiety.
Lot of information there, but don’t get overwhelmed by perfect macro ratios; instead, focus on protein and eat a well-balanced diet. You’ll likely find carbs and fats in a healthy position.
Micronutrients (vitamins and minerals)
Moving on to micronutrients (vitamins and minerals). These are best obtained through dietary variety. Eat a range of colourful foods: Blue/Purple foods are high in antioxidants, green foods are high in vitamin A, yellow/green are high in potassium, orange/yellow foods are rich in vitamin C and magnesium, white/cream foods contain potassium and B vitamins, and red foods contain lycopene, which is essential for natural skin defences. So, shop for colour!
Fibre
Oh, and get your fibre in. The UK average is under 15g/day (AOAC, 2015) – well below what's needed for bowel health and satiety. Aim to include vegetables with most meals and prioritise whole grains, legumes, fruits, nuts, and seeds.
Hydration
Finally, hydration. Hydration supports physical performance and overall health and can even help manage appetite (Vij & Joshi, 2014). Keep a water bottle with you throughout the day.
Parting shot
And that’s it. You manage your calories, get your protein and veg in, and just generally shop for colour, you’ll be smashing it!