Diet and job performance

Estée van Lingen, a dietitian, explains the importance of a healthy balanced diet to enhance job performance.

The modern workplace is often fast-paced and demanding, requiring you to be at your best both mentally and physically. Achieving peak performance in any job, requires more than skills and knowledge, it also depends on the foundation of good health.

A healthy diet plays a crucial role in fuelling the body and mind to help support focus, productivity, and overall job performance. It also prevents staff from being off sick regularly.

The relationship between diet and job performance

What you eat has a direct impact on your energy levels, mood and cognitive abilities. The food you eat can provide your body with the necessary nutrients that helps it to function optimally. Just like a car needs fuel and oil to operate, your body needs the right nutrients to provide it with the best energy possible.

The opposite is also true where the lack of the right nutrients can prevent you from performing optimally and having the correct energy, leading to mistakes in your job. Several studies have linked diet to job performance showing that individuals who maintain a healthy diet tend to have better productivity, decision-making skills and emotional well-being.

A balanced diet for optimal cognitive function

A well-balanced diet consisting of a variety of nutrient-rich foods is essential for maintaining optimal cognitive function. Nutrients such as omega 3 fatty acids, antioxidants, vitamins and minerals are known to support brain health and enhance cognitive abilities. Including unprocessed foods like fatty fish (salmon, trout, mackerel, pilchards and sardines), nuts, leafy greens as well as a variety of vegetables and fruits (especially berries) and whole grains in your diet can significantly contribute to improved focus, memory and problem-solving skills.

Balanced energy levels help to sustain focus

Maintaining steady energy levels throughout the workday is vital for sustaining focus and concentration. Consuming complex carbohydrates, such as whole grains and vegetables, can offer a gradual and consistent energy release. This helps to prevent the energy crashes that are frequently experienced, particularly during the late afternoon, following the consumption of sugary snacks or heavily processed foods.

A steady energy supply ensures consistent productivity and mental clarity, enabling you to perform at your best throughout the day. Small servings of high fibre or complex carbohydrates can be consumed throughout the day, instead of all at once which can lead to a drop in energy levels.

Managing stress and promoting mental well-being

Work-related stress is a common issue that can negatively affect job performance and overall job satisfaction. A nutritious diet can play a role in managing stress by supporting the body’s ability to cope with stressors. Foods like avocados, dark chocolate and green tea contain compounds that have been shown to reduce stress hormones and promote a sense of calmness.

Other activities can also be incorporated to assist in managing stress like breathing exercises, going for a short walk during your work day, doing hobbies or exercising after work.

The importance of hydration

Hydration is another critical aspect of maintaining optimal job performance. Since your body consists of more than 75% of water, and all body processes uses water in some way, dehydration can lead to decreased cognitive function, reduced focus, and impaired decision-making abilities. It’s essential to drink enough water throughout the day to stay hydrated and keep the brain functioning at its best.

The requirements for each person are different and you can slowly build up to your unique goal. Start where you are at, for example, two glasses of water then slowly increase it with another glass per day for the first week then with two glasses the next until you get to about 1,5 – 2 litres of water per day.

If you have very light-yellow urine, it’s a good indication that you are well-hydrated. The darker it is, the more water you need to incorporate. Coffee and caffeinated drinks don’t count towards your water goal as it also dehydrates the body.

While you’re increasing water intake, you also want to decrease intake of caffeinated drinks. Herbal teas can count towards water intake as long as it doesn’t have sugar or honey added.

Customising your diet to your job.

While general dietary guidelines can be helpful, it’s essential to recognise that your needs may vary based on the nature of your job, activity level and personal health conditions. Consulting with a registered dietitian can provide personalised advice on tailoring a diet to meet specific job demands and health goals.

Basic dietary changes to improve the quality of your diet

  • Eat a healthy balanced breakfast. Breakfast doesn’t necessarily refer to eating as soon as you wake up. It’s basically the first meal you have. The key is to choose a time when you regularly have your first meal e.g. daily at 8am or 10am. Include a lean protein with breakfast, for example: eggs, low-fat cottage cheese, high protein cereal or nuts and seeds. Avoid refined and processed starches (white bread, pasta, baked goods) that will drop your blood glucose and spike it during the day, leaving you drained.
  • Have smaller more regular meals instead of one large meal per day. Regular meals can be anything between three to six times per day, but still sticking with your total daily allowance.
  • Don’t replace meals with coffee.
  • Avoid sugary or processed snacks during the day. For example, sweets, crisps, donuts, croissants, muffins, fizzy drinks, energy drinks, etc.
  • Have healthy snacks available that you can snack on when needed e.g. fruit, nuts and seeds, yoghurt, low-carb protein bars, eggs, Provitas with peanut butter or low-fat cottage cheese, avocados (mashed as a dip for raw vegetables or on a Provita).
  • Include protein with most meals as well as fibre in the form of vegetables, grains or legumes. Also add healthy fats to the meal such as olive oil, olives, avocados, nuts and seeds.
  • Plan and pack meals and snacks ahead so that you don’t end up at the office ravenous and ordering in or buying take-out.
  • When take-out is the only option, opt for healthier options e.g. grilled, not fried; have salads without dressings; leave out the chips; don’t add a fizzy drink to the meal; and decrease the portion sizes.
  • Take a break when eating (even if it’s just 10min) and don’t eat while you’re busy working. When you do these two things together, the brain doesn’t register you have eaten or how much you have eaten, and you can easily overconsume food. You’ll also eat much faster when you’re busy working compared to when you focus on what you’re eating which can again affect your digestive health.
  • It’s good to take breaks in between working. For example, when consuming snacks as this will also give a break to your brain so you can be more productive when returning to work. During breaks, you can consume water or walk around which will help you achieve your water and movement goals.

In summary

Maintaining a healthy diet isn’t only beneficial for overall well-being but also plays a crucial role in enhancing job performance and preventing illness and sick days. A well-nourished body and mind can lead to increased focus, sustained energy levels and improved cognitive function, all of which are vital for excelling in any job. By making conscious choices about what you eat, you can pave the way for success in your professional life while prioritising your long-term health and happiness. Remember, a well-fed mind is a powerful tool in conquering the challenges of the modern workplace.

Estée van Lingen is a registered dietitian practicing in Randburg and Fourways, Gauteng. She has been in private practice since 2014 and is registered with the HPCSA as well as ADSA and served on the ADSA Gauteng South Committee for 2020 – 2022.


Estée van Lingen is a registered dietitian practicing in Randburg and Fourways, Gauteng. She has been in private practice since 2014 and is registered with the HPCSA as well as ADSA and served on the ADSA Gauteng South Committee for 2020 – 2022.

Header image by FreePik