As a university qualified nutritionist, I’ve delved into the scientific literature on simple carbohydrates and the affect they have on health. Research shows that a diet high in simple carbohydrates negatively affects mood, energy levels, cognitive ability, anxiety, decision making and more.

You probably already heard that sugary beige foods are not good for us, but they continue to form the main component of many of our diets. Pastries, sweetened granola and cereal, cookies, toast with jam and fruit juice may seem like a list of regular breakfast foods to many, but just because they are common doesn’t mean that they are a good choice to start the day.


Simple carbs and the affect they have on health

There are a number of reasons a diet high in simple carbohydrates are a bad choice, perhaps the most obvious is that these foods quickly break down to simple sugars.

This quick release energy results in a sharp spike in glucose levels & then a crash which may affect mood & energy levels (2). Research shows that within an hour of ingesting a high simple carbohydrate meal fatigue levels increase, & alertness decreases in comparison to a placebo (4).

Regular consumption of high sugar meals has been shown to negatively affect cognitive function, impulse control, decision making & can increase levels of anxiety & depression (3).

These issues can result in a cycle of wanting to eat again & then going through another spike & crash.


What to eat instead of carbohydrates

Benefits of protein

Ensuring you eat enough protein is an important part of maintaining lean muscle mass, strength, function, energy & keeps you fuller for longer. There is an array of essential amino acids found in protein that are necessary for optimal health. Protein comes from a variety of plant & animal sources such as meat, dairy, fish, eggs, legumes, nuts, seeds & soy (1).

The Australian government guidelines recommend women consume 25g of dietary fibre per day and men have 30g per day.


Benefits of a high fibre diet

A high fibre diet is associated with longevity, one study showed a 15 – 30% reduced risk of mortality in comparison to low fibre consumers. Multiple studies also show that a high fibre diet reduces the risk of chronic disease such as heart disease, diabetes, stroke & colon cancer (5).

Favourite high fibre foods include:

  • Avocado
  • Chia seeds
  • Raspberries
  • Artichoke


Healthy fats

Healthy fats are essential for the integrity of every one of our cell’s membranes and for optimal function and supports the growth of new cells.

Types of healthy fats include:

Omega 3 typically found in oily fish and seafood but can also be source from plant foods such as walnuts and flaxseeds.

Oleic fatty acid found in olives can improve heart health, lower harmful cholesterol and reduce inflammation. Diets rich in this omega 9 (Schwingshackl & Hoffmann, 2012) has also been shown to help with insulin sensitivity and lower blood glucose levels (Brehm, et al., 2009).

Hemp seeds are rich in linoleic acid (omega-6) and alpha-linolenic acid (omega-3).

Favourite foods high in healthy fats include:

  • Avocado
  • Hemp seeds
  • Olives
  • Walnuts
  • Pumpkin seeds
  • Wild caught sardines, anchovies, trout and salmon


Complex carbs vs simple carbs

Complex carbohydrates are a different kettle of fish because they can have health benefits, are often nutrient dense and are natural. Conversely you will notice that most simple carb foods are man-made and low in nutrients.

As a nutritionist my favourite complex carbs are:

  • Sweet potato
  • Lentils
  • Green peas
  • Millet
  • Buckwheat
  • Potatoes
  • Quinoa
  • Black beans
  • Chickpeas
  • Steel cut oats


Nutritionist approved meals

As a nutritionist some of my favourite healthy meals that are low in simple carbohydrates, nutrient dense and high in fibre are:

  1. Steel cut oats with hemp, chia and raspberries and blueberries
  2. Eggs with fried tomato and mushrooms
  3. Smoked salmon, avocado, asparagus and sweet potato
  4. Quinoa, organic chicken, rocket, capsicum, artichoke, olives with balsamic and olive oil
  5. Slow cooked lamb with tabouli, chopped onion, tomato, olives and cucumber and a small roast potato
  6. Vegetable and lentil curry with coconut cream with a small serving on brown rice


Key takeaway

Breakfast options that are high in fibre, protein, healthy fats & of course nutrients are the ideal choice.



  1. Brehm, B. J., Lattin, B. L., Summer, S. S., Boback, J. A., Gilchrist, G. M., Jandacek, R. J., & D’Alessio, D. A. (2009). One-year comparison of a high-monounsaturated fat diet with a high-carbohydrate diet in type 2 diabetes. Diabetes care32(2), 215–220.
  2. Cena, H., & Calder, P. C. (2020). Defining a Healthy Diet: Evidence for The Role of Contemporary Dietary Patterns in Health & Disease. Nutrients, 12(2), 334.
  3. Ehrmann, D., Schmitt, A. J., Rubertus, P., Kulzer, B., & Hermanns, N. (2020). 783-P: Can Mood & Energy Levels Be Predicted by Preceding Glucose Values? Combining Ecological Momentary Assessment (EMA) & Continuous Glucose Monitoring (CGM). Diabetes, 69(Supplement_1).
  4. Jacques, A., Chaaya, N., Beecher, K., Ali, S. A., Belmer, A., & Bartlett, S. (2019). The impact of sugar consumption on stress driven, emotional & addictive behaviors. Neuroscience & Biobehavioral Reviews, 103, 178–199.
  5. Mantantzis, K., Schlaghecken, F., Sünram-Lea, S. I., & Maylor, E. A. (2019). Sugar rush or sugar crash? A meta-analysis of carbohydrate effects on mood. Neuroscience & Biobehavioral Reviews, 101, 45–67.
  6. Reynolds, A., Mann, J., Cummings, J., Winter, N., Mete, E., & Te Morenga, L. (2019). Carbohydrate quality & human health: a series of systematic reviews & meta-analyses. The Lancet, 393(10170), 434–445.
  7. Schwingshackl, L., & Hoffmann, G. (2012). Monounsaturated fatty acids and risk of cardiovascular disease: synopsis of the evidence available from systematic reviews and meta-analyses. Nutrients4(12), 1989–2007.



By nutritionist Chrissy

Chrissy is a university qualified nutritionist who graduated with honours at La Trobe University in Melbourne. One of her favourite hobbies is to read the scientific literature on how to optimise health. When she’s not reading, writing or working she’s with her 3 children outdoors, practicing yoga, jogging or cooking up a storm in the kitchen. Chrissy has overcome some debilitating chronic health issues (low mood, adrenal fatigue, insomnia, very bad acne to name a few) with the power of nutrients and correcting gut health, at 39 she now feels better than she did in her 20’s.