Skip to main content
A Dietician’s Guide to Nutrition

A Dietician’s Guide to Nutrition

Many of us have said that we want to tighten up on our health and nutrition. But with endless diets, trends, and conflicting advice flooding our feeds, knowing where to start can feel overwhelming. Let’s bring it back to basics and break down everything from calories, macronutrients, and micronutrients, in a way that’s easy to understand and implement.

Understanding Nutrition and Why it Matters

As a Registered Dietitian, I recognise nutrition can mean something different to everyone. It’s a deeply personal subject influenced by many factors including our upbringing, environment, values, lifestyle, mood, and even hormones. At its core, nutrition is about the relationship between people and their food, not merely just calories and nutrients.

This is why altering our eating habits can be complicated. But ensuring good nutrition is important. Here’s why:

When we don’t provide our bodies with proper nutrition, our bodies can undergo adaptations to minimise the consequences (for example, menstrual cycles can stop), but overtime, deficiencies can arise bringing with them unpleasant symptoms and sometimes serious health consequences.

How Can We Achieve Good Nutrition and What Does Our Body Need?

Calories

Within nutritional science, a Calorie refers to the amount of heat (a.k.a, energy) required to raise the temperature of 1 kilogram of water by 1ºC. In the human body, rather than raising water temperature, calories fuel everything from digestion to walking, either being used immediately or stored for later use. 

How Many Calories Do I Need?

General guidelines suggest 2000 kcal for women and 2500 kcal for men. However, personal needs depend on several factors:

  • Age
  • Gender
  • Activity levels
  • Health status
  • Personal goals

Plus, the above guidelines are based on the average UK adults’ lifestyle, which is sedentary. To calculate energy needs on a more individual basis, multiply your weight (kg) by a ‘Physical Activity Level’ (PAL):

  • Sedentary lifestyle: PAL 1.4-1.6
  • Moderately active: PAL 1.6-1.8
  • Very active: PAL 1.8-2.0

Healthy Weight Loss: Quality Over Quantity

While calories play a role in our health and weight management (should that be your goal), the quality of our diet is just as important – plus, focusing solely on numbers can lead to an unhealthy relationship with food. 

Instead, aim to focus on consuming ‘nutrient dense’ foods – those that provide maximum nutrients per calorie – and minimise your intake of nutrient-poor foods, which are typically those  high in saturated fats, sugar or have been extensively refined or processed.

Nutrient dense foods include

  • Fresh fruits and vegetables
  • Whole grains
  • Legumes and beans
  • Nuts and seeds
  • Fatty fish
  • Lean proteins
  • Eggs

With that said, however, it is important to note there are no ‘good’ or ‘bad’ foods. Instead, when we view food for its nutrient density, we can begin to appreciate that there are merely foods that offer an abundance of nutrients and foods that provide only a small amount or narrow range of nutrients, and it’s their place in our overall diets that determine their impact. It is only when the latter foods make up the majority of our daily intake that our risk of falling short of certain nutrients can increase.

Bonus Tips for Healthy Weight Management:

  1. Listen to your body’s hunger and fullness signals (practice mindful eating)
  2. Prioritise whole foods most of the time
  3. Stay hydrated
  4. Maintain regular physical activity

Remember: sustainable weight management is about nourishing your body, not restricting it.

Macronutrients: The Building Blocks of Nutrition

So, now we know the quantity and quality of food we should look to consume, but what about the composition of our diets?

Carbohydrates

Purpose: The body’s main energy source, providing quick energy to the brain and muscles, and supporting digestive health through providing fibre.

Sources

  • Whole grains (wholewheat bread, pasta, and rice, quinoa, buckwheat, oats)
  • Fruits and vegetables
  • Legumes and beans

UK Recommended Daily Intake: 50% of daily calories*

Proteins

Purpose: Supports muscle growth, repair, immune function, and maintaining healthy hair, skin and nails. Read our recent article for more on the benefits of protein.

Sources

  • Tofu and tempeh
  • Legumes and beans
  • Nuts and seeds
  • Lean meats
  • Fish and seafood
  • Eggs and dairy, and dairy alternatives

UK Reference Nutrient Intake: 0.75g protein per kg of body weight per day*

Fats

Purpose: Essential for brain health, hormone production, and absorbing fat-soluble vitamins.

Sources

  • Avocados
  • Nuts and seeds (and their spreads)
  • Extra virgin olive oil
  • Fatty fish
  • Chia seeds and flaxseeds

UK Recommended Daily Intake: no more than 35% of daily calories*

*These recommendations are guidelines only. Nutritional bodies agree there is no one single optimal ratio for macronutrients; it is entirely dependent on one’s personal preferences, health status, and athletic goals

Micronutrients: The (slightly smaller) Building Blocks of Nutrition

All micronutrients are important for optimal health, but in the interest of keeping this blog easily digestible (pun intended), below we have discussed just a handful of these. For a more exhaustive list and breakdown of micronutrients see here

Vitamins 

  • Vitamin C: Supports bone and teeth formation and integrity, and the immune system (found in citrus fruits, broccoli, cauliflower, berries)
  • Vitamin D: Promotes calcium absorption to support bone health (sourced from sunlight, fatty fish, fortified foods)
  • B vitamins: Each B vitamin has its own unique role, but a main role is to help convert food into energy (found in whole grains, fruit and vegetables, meat and dairy, fortified foods)
  • Vitamin A: Supports vision, immunity, and healthy skin (found in spinach, carrots, sweet potatoes, red peppers, dairy, oily fish)

Minerals

  • Iron: supports the formation of connective tissue, hormones, and red blood cells, which carry oxygen around the body (found in fortified cereals, lentils, wholegrain bread, leafy greens, and tofu)
  • Calcium: Builds strong bones and teeth, supports the nervous system, and cardiovascular health (found in tofu, legumes, green leafy vegetables, dairy, fortified plant milk)
  • Magnesium: Supports muscle and nerve function, blood pressure and blood sugar regulation, and the production of bone, proteins, and DNA (found in nuts, spinach, bananas, avocados, oranges, wholegrains)
  • Zinc: Supports the immune system, wound healing, thyroid function, and DNA synthesis (found in fortified breakfast cereal, tofu, hemp seeds, tahini, cashews)

Supplementation

While eating a diet that provides sufficient calories and contains a variety of fruits, vegetables, whole grains, lean proteins, and healthy fats will usually meet your nutrient needs, there are some cases where special consideration or supplements may be necessary. Common situations include:

  • Athletes: May need additional protein and carbohydrates.
  • Vegetarians/Vegans: May need increased consideration for certain nutrients such as B12, iron, calcium and protein, amongst others.
  • Older Adults: May need additional calcium, vitamin D, and protein.
  • Pregnant: Can have higher nutrient needs at different stages of pregnancy.

Always consult your healthcare provider before starting any supplements to ensure they are safe and appropriate for you.

Final Thoughts

Nourishing your body does not have to be confusing or based on numbers or trends. By understanding the fundamentals—calories, macronutrients, micronutrients, and the quality of your food choices—you can create a sustainable and enjoyable eating pattern that aligns with your personal goals. And remember, as we embrace the fresh start that January offers, approach your nutrition journey with curiosity and kindness.