Two women in an office kitchen looking at a phone

Managers: Eat to Be Productive

  • Productivity level is measured by dividing average output per period by the total costs incurred or resources consumed in that period.
  • However, the ‘’output’’ of a manager is the result of a more complex equation with many variables.
  • Two main factors that help us achieve high productivity have to do with limiting distractions and being able to think clearly and focus. Rita Makri, Registered Dietitian at AXA Health, discusses how nutrition can effect our productivity levels.

Have you ever thought of food as a distraction? Well… every time you skip a meal, or you choose a ready-to-eat, processed snack, would you believe that counts as a distraction?

It is possible to change your mentality of food whilst working and use it to your advantage. There is the right time for everything, and we could all agree that during a jam-packed day meal planning is often not a priority. One might wonder: “If that is the case, how much does it really affect my productivity?”

Let’s talk glucose levels

Glucose is virtually the sole fuel for the human brain, except during prolonged starvation. The brain lacks fuel stores and hence requires a continuous supply of glucose. It consumes about 120g of glucose daily, which corresponds to an energy input of about 420 kcal (1760 kJ), (equivalent to 1 bar and a half of chocolate!) accounting for some 60% of the utilization of glucose by the whole body in the resting state. Overall, glucose metabolism remains unchanged during mental activity, although it is suggested that glucose metabolism increases when we perform certain tasks.

In starvation, ketone bodies generated by the liver partly replace glucose as fuel for the brain in order for us to function. As a manager, it can be easy to skip/work through lunch due to a busy workload but it’s vital to understand how important nutrition has on our productivity levels. Overall, it is better for us to eat little / small amounts often rather than avoiding foods for longer periods in order to maintain and stabilise our glucose levels throughout the day and keep our productivity levels high.

High blood sugar may add to mental decline in people with cardiovascular disease. Scientists are looking to prove that even single cases of high blood sugar to people that are not diabetic cause inflammation in the brain which may lead to permanent damage. On the other hand, episodes of very low blood sugar (hypoglycaemia) that are followed by seizures or loss of consciousness can also have a lasting impact on thinking and memory.

Top Tips to Maintain Your Glucose Levels

  • Low-carb diets are better tolerated by the brain, rather than the no-carb diets. Remember carbohydrates give our body the energy it needs to survive.
  • Set your alarm! Have you ever felt hangry? If you wait too long before you next have something to eat, your blood glucose is already at its lowest. Let your phone, watch or computer remind you that is time for a snack before you start feeling dizzy or grumpy.
  • Prepare your snacks before you start working, that way you can have them next to your desk or on side prepared. Washing some fruit or making a small bowl of dried fruit and nuts shouldn’t take long. If you fail to spare a few seconds to grab it, it will stay there reminding you that you can do better next time!
  • Do not exaggerate when translating your needs in glucose. It is highly unlikely for the healthy population to need a slice of cake or a chocolate bar in order to bring their sugar levels back to normal.
  • Make use of last night dinner leftovers for lunch. Is there a chance that you could incorporate this piece of dry grilled chicken breast in a Caesar’s salad, an omelette, a sandwich or a sauce that can go over some wholemeal pasta? It is easier to get inspired and motivated to prepare a quick meal when there is a key ingredient that can serve as the starting point.
  • Think of a Plan B! Be a smart shopper and make sure that, in case there is absolutely no to time to prepare a proper meal, you can find foods in your kitchen that complement each other, e.g. canned tuna, wholemeal crackers and some cucumber or canned beans and toast.

Supplements vs Real Food

It is safe to say that most supplements are not tested rigorously in clinical trials. However, we are going to take a closer look at the most popular nutrients and vitamins that promise better memory and brain function. These are the omega-3 fats (EPA, DHA, ALA), vitamins E, B6, B9 (folate) and B12.

Omega 3 fats have been shown to regulate the growth of new brain cells and maintain fluidity of cell membrane as well as helping to improve our behaviours, our mood and our cognitive function. EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) are two main types of fatty acids which are found mostly in fatty fish and ALA (alpha linolenic acid) is found in leafy green vegetables, vegetable oils, nuts and seeds. The body converts ALA into EPA or DHA, but only in small amounts, so the best way to get high amounts of EPA and DHA is by eating more fish, oily fish in particular.

In the UK, there are no specific recommendations of omega 3 dosage for the general population (BDA, 2017). The Scientific Advisory Committee of Nutrition (SACN) continues to endorse the guideline recommendations that everyone should try to eat at least two portions of fish a week, of which one should be oily. One portion is equal to 140g and most of the UK population struggles to eat this much.

Think about including some mackerel, kippers, pilchards, herring, salmon, sardines or sprats into your diet regularly. Fresh and canned tuna do not count as oily fish. (NHS, 2018). Mackerel on toast or a grilled salmon salad can be a perfect meal to have for lunch to boost your mood and help you focus for the afternoon ahead. If you don’t like fish, try to include more nuts and seeds (walnuts, sunflower and pumpkin seeds), green leafy vegetables, tofu and beans to increase your omega 3 levels.

Oily fish can contain low levels of pollutants and chemicals which can build up in our bodies and cause harm. There are maximum recommendations for the number of portions some groups of people should be eating each week and types of fish we should be eating.

  • Pregnant and breastfeeding women, girls and women who are planning a pregnancy should eat no more than two portions of oily fish per week.
  • Shark, swordfish and marlin may contain concentrated levels of mercury which can be harmful to a developing baby’s nervous system so these types of fish should be avoided by women who are pregnant, planning for a child and all children under the age of 16. All other adults should eat no more than one portion of these particular fish a week. (NHS, 2018).
  • Women past childbearing age or not intending to have children, men and boys can eat up to four portions of all other oily fish a week.

The health benefits of regularly consuming oily fish such as, improved cardiovascular health and improved cognition, appear to outweigh the risks of pollutants. (BDA, 2017, SACN, 2004). Choose fish from sustainable sources where possible and be aware of the recommendations for specific age/gender groups.

Vitamin E has been found to have a positive benefit on our brain health. As an antioxidant, it is believed to help with brain health by reducing oxidative stress. Oxidative stress is a natural process of ageing which can cause damage to our cells and tissue but can be influenced by our lifestyle choices. Think about including foods such as a variety of nuts and seeds (almonds, sunflower seeds, unsalted peanuts), avocados and dark green leafy vegetables like spinach and swiss chard.

Researchers found that high doses of vitamin E may help people with mild to moderate Alzheimer's dementia continue to perform daily life functions, but only for a short period of time. Vitamin E does not prevent the disease or reduce other symptoms, though, and high doses increase the risk of haemorrhagic stroke.

B6, B9 and B12 are often linked with brain health, they can help break down homocysteine (which is a naturally occurring amino acid). High levels of homocysteine have been associated with a greater risk of dementia and Alzheimer's disease. On the other hand, B vitamins also help produce energy needed to develop new brain cells. Having said that, since most people get enough B vitamins through their diet (eggs, meat, fish, dairy, fruits, wholegrains), B vitamin supplements do not have any clear benefit for brain health and are only recommended in the uncommon cases of deficiency.

Top tips if you are considering supplements

  • Trust a varied and balanced diet more than the supplements. Always consult a GP or registered health professional before taking any form of supplement.
  • Choose an omega-3 oil as opposed to a fish liver oil.
  • Look out for vitamin A content – the SACN advises that if you take supplements containing vitamin A, you should not have more than a total of 1.5mg a day from food and supplements combined.
  • Pregnant women or those planning for a baby should not take supplements containing vitamin A as too much can be harmful to an unborn baby.

How do I stay alert when working from home is too comfy?

Ever thought that working from home makes you crave a nap even more? Nutrition can prove to be your friend one more time and help you top up your energy levels!

Consider your lunch – Large portions of high saturated fat and processed meals that require too much effort from the stomach and the gut in order to be digested could deprive the brain from the energy that it needs.

Another key factor that could make us feel sleepy and less productive is dehydration. Dehydration can cause irritability and have a reduced effect on our cognitive function. Try your best to measure the volume of fluids that you get to make sure that it is enough (2-2.5 litres per day) and remember that beverages with caffeine or alcohol have a diuretic effect. That means that we cannot rely on coffee and spirits to get hydrated, but a normal consumption couldn’t cause dehydration. Moreover, caffeinated beverages will not always make up for the time of sleep you missed last night and too much of them can even lead to insomnia and headache. Remember the importance of work-life balance and switch off from work when you finish.

If you suspect an iron or vitamin deficiency is what is making you feel tired, you should visit your GP, requesting for some blood tests and get a diagnosis before considering buying supplements. When the deficiency is confirmed, your GP will suggest the diet or the correct dose of a supplement and the amount of time that it should be taken.

Top tips when working from home

  • Avoid overeating during lunch time, especially high saturated fat foods.
  • Include healthy snacks such as fruits, nuts and seeds to keep you going throughout the day.
  • Stay hydrated mostly with plain or flavoured water and fruit juice.
  • Try not to schedule meetings or deadlines over lunch time so you have the opportunity to take a break and encourage your team to do the same.
  • Do not overestimate what coffee and energy drinks can do for you.
  • Do not “self-medicate” with supplements.

Take home message – conclusion

Being your best self physically and mentally go hand by hand. Reasonable quantities of good quality, fresh and varied food will give you all the boost needed to have a smashing day every day!


Biochemistry, 5th edition, Jeremy M Berg, John L Tymoczko, and Lubert Stryer, New York: W H Freeman; 2002. ISBN-10: 0-7167-3051-0
Bosch, C, A., O’Neill, B., Sigge, O, G., Kerwath, E, S., & Hoffman, C, L. (2016). Heavy Metals in Marine Fish Meat and Consumer Health: A Review. Journal of the Science of Food and Argiculture, Jan 15;96(1):32-48. doi:10.1002/jsfa.7360.

British Dietetics Association. (2017, September). Food Fact Sheet - Omega-3. Retrieved from here.
BusinessDictionary. (2020). Productivity. Retrieved from here
Harvard Medical School. (2020). Sugar and the brain. Retrieved from here
NHS. (2018, 4 December). Fish and shellfish. Retrieved from here.

Scientific Advisory Committee on Nutrition. (2004). Advice on fish consumption: benefits & risks. Retrieved from here