Once we understand why we eat and how much to eat, the next big question is: what should we eat?
There’s no shortage of opinions on this. From low-carb to plant-based to intermittent fasting, the internet is full of advice—and most of it promises quick results. But at CrossFit Kreis 9, we approach nutrition through a different lens: what does your body need to function, perform, and feel its best over time?
The answer lies in two main categories: macronutrients and micronutrients. You need both, in the right amounts, and from a variety of sources.
Let’s break them down.
Macronutrients: the big picture
Macronutrients are the nutrients your body needs in large amounts. They provide energy (calories) and structure for your body’s daily functions and performance. There are three main macronutrients:
1. Protein
Protein is made of amino acids, the building blocks of muscle, tissue repair, enzymes, and hormones. It’s essential for recovery, strength, and long-term health.
- Helps preserve lean muscle mass
- Supports immune function
- Keeps you feeling fuller for longer
- Critical after training or physical activity
- Can be found in: meat, fish, eggs, dairy products, tofu, tempeh, legumes, and protein powders
2. Carbohydrates
Carbs are your body’s preferred fuel source. They power your workouts, your brain, and your central nervous system. Contrary to popular belief, carbohydrates are not the enemy—they’re a performance and recovery tool.
- Help refill muscle glycogen after training
- Support endurance, strength, and intensity
- Include fruits, vegetables, whole grains, legumes, and dairy
- Can be found in: oats, potatoes, rice, bread, lentils, beans, fruit, and starchy vegetables
3. Fat
Fats are essential for hormone production, brain function, and absorbing fat-soluble vitamins (A, D, E, K). They also make meals more satisfying and flavorful.
- Include sources like olive oil, nuts, seeds, avocados, fatty fish
- Necessary for long-term health, especially in aging populations
- Do not need to be feared—but portion size matters, since fat is calorie-dense
- Can be found in: olive oil, nuts, seeds, avocado, eggs, cheese, and oily fish like salmon
None of these macronutrients should be eliminated. Your body needs all three. The right balance depends on your lifestyle, goals, and preferences.
How much of each macronutrient?
While exact needs vary depending on your goals and activity level, here are some general guidelines that work well for most active adults:
Protein
- 1.6–2.2 g per kg of body weight per day
- Higher end (2.0–2.2 g/kg) if you’re training hard, trying to build muscle, or in a fat-loss phase
- Example: A 70 kg person would aim for 112–154 g of protein daily
Carbohydrates
- 3–6 g per kg of body weight per day, depending on training intensity and goals
- Lower end if training is lighter or weight loss is the goal; higher end for athletes or multi-session training
- Example: A 70 kg person may need 210–420 g of carbs daily
Fat
- 0.8–1.2 g per kg of body weight per day
- Important for hormone health, brain function, and satiety
- Example: A 70 kg person would aim for 56–84 g of fat daily
These are starting points, not rules. Your needs may shift with seasons of life, training volume, and personal goals.
Micronutrients: the small essentials
Micronutrients are vitamins and minerals that your body needs in smaller amounts—but they play a huge role in keeping you healthy.
They regulate everything from:
- Bone density
- Energy metabolism
- Mood and mental clarity
- Immunity
- Sleep quality
- Muscle function
Unlike macronutrients, your body can’t create most micronutrients on its own. You need to get them from your diet—especially from whole, minimally processed foods.
Examples include:
- Iron, magnesium, zinc, calcium – vital for oxygen transport, recovery, bone health, and energy
- Vitamins D, C, B12, A – crucial for immune support, nerve function, and more
- Electrolytes like sodium and potassium – especially important for hydration and training
Fibre: the overlooked essential
Fibre isn’t a vitamin or a mineral, but it’s just as important. Found in plant-based foods like vegetables, fruits, legumes, nuts, seeds, and whole grains, fibre plays a critical role in:
- Digestive health – helps keep your gut working properly
- Blood sugar regulation – slows digestion and supports energy stability
- Cholesterol control – binds to excess cholesterol and helps remove it
- Satiety – helps you feel full longer and prevent overeating
Most people don’t get nearly enough fibre. If your meals are mostly refined, low-volume, or lacking plants, it’s easy to miss the mark—even if you’re eating enough calories.
A fibre-rich diet is one of the simplest and most powerful ways to improve both short-term performance and long-term health.
Can you eat too many nutrients?
From whole foods? Almost never.
Your body is very good at regulating and excreting excess vitamins and minerals when they come from natural sources. The real problem isn’t overdoing it—it’s not getting enough. Nutrient gaps are surprisingly common even in people who eat enough calories.
It’s easy to eat too much energy and still be under-nourished. That’s why we emphasize nutrient-dense choices—not just portion control.
What about supplements?
Supplements can help in specific situations:
- Vitamin D in winter
- Protein powder for convenience
- Creatine or omega-3s for training support
But they’re called supplements for a reason—they’re meant to fill gaps, not replace real food. If your diet is poor, no supplement can fix the foundation.
In summary: What should we eat
What you eat matters.
You need:
- Macronutrients for energy, performance, and recovery
- Micronutrients for health, function, and longevity
- Fibre for digestion, satiety, and disease prevention
- A variety of real foods to cover all of the above
You don’t need extreme diets, strict meal plans, or superfoods. You need to eat enough of the right kinds of food, consistently. The goal is nourishment—not restriction.
Understanding these foundations is part of how we support our members through nutrition coaching at CrossFit Kreis 9—built around real life, not rigid rules.
Next up in the series: How to change eating habits
