May 23, 2022
Energy is used for every process in our body, from breathing and digestion to work and exercise – and that energy comes from the food we eat. The amount of energy contained in a food is measured in calories. Our Nourish Drinks, for example, contain between 495 and 577 calories – the perfect amount to be used as a meal alternative or an energy-boosting supplement to fuel your day.
How much energy do we need?
We need a minimum amount of energy for our body to conduct the basic functions that keep us alive. This includes breathing, cell production, our body temperature, heartbeat, blood circulation and processing of nutrients.
That number will depend on our age, height, body composition and sex at birth, and is known as our basal metabolic rate (BMR) – basically, the amount of energy used to keep us alive if we stayed in bed all day. Perhaps surprisingly, our BMR uses up 60 to 70 per cent of all the calories we consume each day.
Of course, most of us don’t stay in bed all day and so need additional energy to go about our everyday lives. Even if we are unwell and aren’t able to be as active as we would like, providing our body with more energy than our BMR is essential. The food we eat can give our body the fuel it needs for repair and recovery. Severe illness may also cause our body to burn huge amounts of calories, known as cachexia, which leads to muscle wasting and rapid weight loss.
Whether we need energy to keep us going through the juggle of our work-life balance, we want to fuel an activity such as exercise or dance, or need to provide our body with the nourishment it needs to help us cope with illness and its treatment, how and what we eat is key.
If you want to work out your own BMR, try this Basal Metabolic Rate Calculator from Diabetes UK.
How food gives us energy
The starch, sugar and fat in the food we eat is broken down into glucose, which is absorbed by the stomach and small intestine and released into the bloodstream, where it can be used immediately or stored for later.
For the glucose to be accessed, the body needs to release insulin. The insulin acts like a key that unlocks the cells, allowing the glucose to move out of the blood and into the cells. The cells then convert the glucose to be energy to be used straightaway or stored for later.
When we eat high-sugar foods, or we overeat, it creates a surge of glucose in the blood. The body responds by flooding our system with insulin, causing blood sugar levels to crash – leading to the classic energy roller coaster than can leave us feeling drained and exhausted, and reaching for another biscuit as a quick energy ‘fix’.
For balanced energy that will fuel and sustain us throughout the day, we need to find the Goldilocks balance of glucose and insulin – not too little and not too much.
If we give our body more energy than it needs, it will store any excess as fat, leading to weight gain. If we don’t give our body enough to eat, it will use our fat stores, leading to weight loss. When our fat stores are depleted, the body will then turn to burning muscle for fuel, causing weakness that can seriously impact on our ability to recover from illness and look after ourselves.
Choose foods to give you energy
When I’m working with my patients, my aim is to help them achieve a balanced diet – including lots of the foods they love – so that they have the energy they need to live their lives to the full. Which is why it’s what we eat, not just the number of calories a food provides, that’s so important.
The Eat Well Plate is an easy way to see the balance of starchy foods, protein, fats, sugar, dairy foods, fruits and vegetables to aim for during a day. Eating this way dials you in to natural ways to boost energy with food.
Starchy foods include grain-based carbohydrates such as wholegrain bread, brown rice, oats, plus sweet potatoes and pulses. Wholegrains and complex carbohydrates take more time to be broken down by the body, so they release their energy over time to keep you going. And because they haven’t had all the goodness stripped out, they contain more fibre and nutrients than processed alternatives, making them a healthy choice in your energy tool kit.
Protein sources include sustainably sourced fish, lean unprocessed red and white meat, beans and legumes, eggs and soya products such as tofu. These protein foods are invaluable when you want to boost your body’s strength and stabilise energy levels. The will also help to provide amino acids to counteract any muscle breakdown caused by your body’s energy needs.
Fats can strike fear into those of us brought up to fear them by weight-watching parents (and the media), or if we have an issue with disordered eating. But good fats, particularly the omega 3 essential fatty acids found in fish, nuts and seeds, are needed for our body to function well – and help us to feel full and energised. Find out more in our blog Fat: Don’t Fear the F Word.
If you know you need food to give you energy, but you’re struggling to eat enough, our blog on best foods when you have loss of appetite can help.
Sugar can provide an instant energy fix, as it’s rapidly taken into the bloodstream as sugar – it’s why we so often crave sweets, chocolates and biscuits when we are tired and rundown. The trouble is, this rapid sugar fix is followed just as swiftly by a sugar crash. The answer is to eat a little protein alongside the sugar, as this helps to slow down its absorption and provide a more sustained source of energy. It’s why our Nourish Drinks contain a balance of carbohydrates and protein to keep you feeling full and energised for longer.
One tip to note: when we are poorly, some of the healthy eating rules around sugar can be relaxed, as that extra boost from having something sweet can give you the boost you need to sit up and eat a more balanced meal (even if it’s a small one) afterwards.
My blog Foods for Resilience and Recovery has more insight into this.
Dairy foods including cow’s milk and cream provide an easily accessible and balanced source of protein and carbohydrates – it’s why dairy forms the basis of our Nourish Drinks. When you’re lacking in energy, enjoying a Nourish Drink, or some Greek yoghurt and fruit, can help give you the boost you need.
Fruits and vegetables may not be particularly energy dense (unless it is the starchy vegetables, such as potatoes and yams), but their high fibre content fills you up to help you feel satiated, while they provide a whole host of antioxidant nutrients associated with lower risk of chronic disease.
A note of caution: if you have loss of appetite and can eat only small amounts, then bulking out meals with a lot of fibre will reduce the quantity of protein and carbohydrates you take in. In this situation, a low-fibre diet can help you get sufficient nourishment. I explain more in my video, When You Need a Low-Fibre Diet.
The lowdown of foods that give you energy
While every food contains calories that will provide your body with energy, not all foods are created equal. Highly processed foods that are high in sugar and salt foods don’t provide the nourishment you need and will leave your body craving more food to fill this nutritional black hole.
Instead, choose nutrient-dense foods that provide more vitamins and minerals in every mouthful, like our Nourish Drinks. For steady energy release, try to ensure every meal contains complex carbs, lean protein and heart-healthy fats.
Nourish Drinks are a superb energy source and can be used to provide an extra boost when you’re flagging in the middle of the day – as Michael Aarons explains in his blog post, ‘I’m training to be a doctor and Nourish Drinks are fuelling my studies’.
For more ideas, read our blog 10 Best Foods for Energy.