Food fuels our bodies and brains, which means that eating well throughout the day is one of the most effective ways of improving productivity.
“Our food choices affect our cognitive performance,” says Fiona Geaney, a registered public health nutritionist, and CEO of Food Choice, a company that supports healthy eating in the workplace. “Eating well can improve our ability to concentrate, our memory, reaction time, problem-solving ability, energy levels and overall mood.”
At first glance, the relationship between food and performance seems simple. We eat food. Our body converts it to glucose and glucose gives us energy we need to function.
But it’s a little more complicated than that. Take when we’re hungry as an example.
“When glucose levels are low, we lack energy and find it more challenging to concentrate and complete tasks,” says Geaney. “That’s why we find it hard to focus when we’re hungry at work.”
It’s easy to reach for the croissants or crisps as a quick fix. But, according to Ali Cunningham, a registered dietitian at the Dublin Nutrition Clinic, we need to focus on nutrition instead.
Carbohydrate-rich foods such as bread, pasta, rice, potatoes, and cereals provide us with most of our glucose. “The average brain uses 120g to 140g of glucose per day,” says Cunningham. “If we don’t meet this requirement, our energy levels and concentration will suffer.”
Our mood can suffer too. “When blood glucose levels dip, it can lead to irritability,” says Cunningham.
Eating regular balanced meals and snacks will help to prevent this dip.
“A balanced meal should be made up of one-quarter carbohydrates, preferably those that are high in fibre and have a low glycaemic index like oats, wholegrain breads and new potatoes,” says Cunningham. “These carbohydrates are digested slowly, which means a slow release of energy over a longer period of time, and helps maintain energy levels and avoid that 3pm slump.”
Protein — in the form of eggs, fish, meat, tofu or beans — should take up another quarter of our plate. “It slows the digestive process further and keeps us feeling satisfied for longer,” says Cunningham.
The other half of our plate should consist of fats, fruits and vegetables, which contain the nutrients necessary for our immune system to work.
“If we’re deficient in nutrients like vitamin C, iron and zinc, our defences will be down, we’ll be prone to illness and we’ll have more sick days from work,” says Cunningham.
Knowing this is one thing. Putting it into practice is another.
Most of us work eight-hour days and have other responsibilities to fit into our remaining waking hours. It’s all too easy to grab what’s most convenient at mealtimes.
This is why Cunningham recommends making a plan. “It can be really difficult to juggle work, family life and healthy eating,” she says. “But prioritising our health doesn’t have to be complicated or overly time-consuming. It can be as simple as taking 30 minutes at the start of every week to pick out six or seven dinners and then shopping for the ingredients for those dinners as well as some nourishing snack options to keep you going throughout the week.”
Geaney agrees. “Planning your meals and snacks ensures you buy less processed foods, have a healthy option waiting with hunger strikes, saves you time and money, and reduces food waste.”
Make sure you buy some breakfast foods while you’re shopping. Too many of us skip this meal, which can have repercussions later in the day.
“Skipping breakfast means blood glucose will dip mid-morning and when it dips below a certain level, hunger signals will be sent to the brain, which usually translates to sugar cravings,” says Cunningham.
“When blood glucose dips, we don’t tend to crave fruit or vegetables but simple sugars like biscuits. Our brains literally ask us for a quick supply of glucose.”
Regularly skipping breakfast can also have serious long-term health consequences. A 2021 study found it made us more susceptible to heart disease, high blood pressure, diabetes, obesity and high cholesterol.
Powering up with coffee can be problematic too. “Caffeine can provide a quick burst of energy but too much can increase anxiety and depressed feelings and disturb our sleep,” says Geaney.
A good breakfast will set you up for the day and it doesn’t have to be elaborate. “A high-fibre cereal with milk and fruit is a convenient option for many,” says Cunningham.
Geaney finds that batch cooking helps with healthy eating.
“It’s a great way to save time and plan for busier days,” she says. “By cooking extra, you can have leftovers for lunch the next day or freeze them for future use. Stews, casseroles, curries and soups all work well.”
There are lots of advantages to having leftovers for lunch. “You know that there’s no hidden saturated fat or added sugar or salt as you have prepared it,” says Geaney.
“Also the food is within arm’s length when you want it. We tend to make poorer food choices when we are hungry, so it helps to plan ahead and have a healthy option ready. And it’s time-efficient. Rather than running out to a restaurant or queuing for a sandwich, you have more time at lunchtime to build in some exercise or relax ahead of the afternoon shift.”
On those days that you don’t bring your lunch to work, Geaney advises steering clear of instant fillers: “Simple carbohydrates such as those found in white pasta and fizzy drinks give us energy, but this can soon be followed by an energy slump.”.
“Excess portions of carbohydrate-rich or high-fat foods like pizza or chips can leave us feeling tired or groggy because they force our digestive systems to work harder.
“Lunch options that help us avoid these outcomes include tuna with pasta and vegetables, vegetable omelette with wholegrain bread or chicken salad in a wholegrain wrap.”
If what we eat for lunch is one consideration, how we eat ought to be another. Cunningham encourages us to eat away from our desks.
“Food is more than just nutrition,” she says. “It has an important social aspect and eating with colleagues can help with mood and with workplace morale. It gives our brain a rest from work. And when we eat at our desk, we’re more prone to mindless eating and eating past the point of fullness.
“What’s more, we tend to eat more quickly, not chewing enough. We swallow more air, which makes it harder for our digestive system to break down our food, leading to bloating and wind.”
Adequate hydration is essential.
A 2014 study found that not drinking enough water can lead to poor productivity, reduced cognitive ability and slower reaction times.
“Most of us need to drink two litres of fluid per day but this varies by age, how hot it is and how active you are,” says Cunningham. “It’s a good idea to start the day with a glass of water and to keep a bottle or glass of water on your desk to sip throughout the day.”
Whether it’s keeping a water bottle on your desk, batch-cooking your meals, or ensuring you have healthy snacks at hand, eating well at work is all in the planning. As Geaney says: “it’s about making the healthy option the most convenient one”.