Dietary Analysis - Fit by Kat

Hello everyone! Today i’ll be sharing some of my uni knowledge on dietary analysis. Now, if you know me (or have read my ‘About Me’ page), you know I’m studying Sports & Exercise at university. It’s content heavy and there’s so much to learn, but I love pushing the boundaries of my mind and learning more and more things that I didn’t even know existed. Not to mention, feeling super intellectual too! Haha.

As much as I love writing about the mind and soul, today I’m getting my nerd on and writing about the body! Specifically, dietary analysis. As the name suggests, this means analysing your diet, such as the nutritional content of the foods you consume, calories in VS calories out, and how this affects weight.

It involved a 3 day experiment of documenting my foods and I found it pretty fun! So give it a read and you might learn something new!

*NOTE: This is a personal study and does not qualify as accredited advice. Additional sources and expert advice for your own dietary analysis is recommended.


Dietary analysis can be used for general or specific populations for a range of purposes, such as identifying health problems or tweaking nutrition to achieve goals (Coates et al. 2017). In a time where obesity has rapidly risen from a few decades ago (World Health Organization 2018), an understanding of energy intake and energy expenditure is advantageous and important.

From an individual perspective, my main fitness goal focuses on maintaining my current weight and physique. However, I highly enjoy attending the gym on average 3 sessions per week lifting weights for strength and hypertrophy.

  • Weight at start of 3-day period: 72.1kg
  • Weight at end of 3-day period: 72.0kg


I recorded all food and activity over the same 3-day period in the computer program Foodworks. I recorded my food and activities throughout the day as they occurred, and also recorded it the night before when knowing what I would be consuming the following day.

Determining the energy cost of activities took consideration to ensure it was accurate. For this, I checked energy cost tables with examples of physical activities to help in deciding the intensity of the activities undertaken.


Upon the 3 day analysis, the mean values were as follows:

  • Daily energy intake over 3 days – 10 503.33 kJs
  • Daily energy expenditure over 3 days – 11 884.18 kJs
  • Carbohydrates – 43.94g
  • Fats – 31.11g
  • Protein – 21.35g
  • Alcohol – 0.00
  • Fibre – 27.31g
  • Calcium – 1057.78mg
  • Iron – 12.57mg
  • Using the World Health Organisation (WHO) formula, the resting metabolic rate (RMR) was found.
  • The kJs consumed over the 3-day period were similar, with less than 2000 kJs difference between the highest day of kJs consumed with the lowest kJs consumed.
  • There were no major outliers in daily intake of macronutrients and micronutrients.
  • The 3-day food report therefore shows a consistent pattern of eating habits, exhibiting roughly a carbs, fats, protein ratio of 45:35:20
  • The intake of fibre, calcium and iron remained alike over the 3 days.
  • The average daily intake over the 3 days was 10 503.33kJs. This is higher than the 8700kJs which is the general recommended guidelines (Government of South Australia 2017), however does not take into account physical activity. The average daily energy expenditure was in fact more than the energy consumed.


A negative energy balance refers to when there is more energy leaving the body than there is coming in (Guyenet & Schwartz 2012). The average results of the 3-day period show a slight negative energy balance, meaning I used up more energy than the amount of food consumed.

My goal to maintain my current weight would require an equal energy balance, however this is unrealistic to perfectly achieve every day. The slight negative energy balance still adheres to the goal of maintaining weight as it does not cause major weight gain or weight loss.

Overall, in this dietary analysis, the energy expenditure was more than energy intake over the 3-day period, which accounts for the slight decrease in weight.

Outcomes of a Positive Energy Balance

  • A continual positive energy balance can cause fat/weight gain
  • May cause muscle atrophy with lack of exercise
  • Thereby in the future lead to health issues such as cardiovascular disease and obesity (Biolo et al. 2008, World Health Organization 2018)
  • A positive energy balance as part of a ‘bulking’ program in short term can result in increased muscle and help specific athletes (Tarnopolsky 2008).

Outcomes of a Negative Energy Balance

  • Can promote fat oxidation and weight loss in the correct context (Janssens et al. 2013).
  • Similar to a lack of exercise causing muscle atrophy, a lack of kJs when training may also result in loss of muscle (Carbone, Mcclung & Pasiakos 2012).
  • A negative energy balance from avoiding food may lead to malnutrition from not consuming enough foods and nutrients.
  • Furthermore, a lack of vitamins and minerals may result in the human body unable to function to its ability. Certain mineral deficiencies may produce things like tiredness, dizziness, and lack of focus (Prasad 2012). Loss of vitamins may result in loss of antioxidants, immunity health, vision, and metabolism processes (Fitzpatrick et al. 2012).
Dietary Analysis - Fit by Kat

Comparing the average values from the 3-day record to the recommended daily intake values from the Australian Government (2006) exhibit an adequate and healthy intake of nutrition.

Although, one major difference found in my dietary analysis was my larger intake of protein than what is recommended, which may be attributed to eating more than the recommended portion size, for meal size and satiety. This aids in muscle recovery and growth with the current strength and hypertrophy training.

A recommendation to reduce the protein intake would be to swap some protein heavy foods at dinner for more healthy fat foods, such as fish. Fish like salmon is still a great source of protein but mainly a fatty food, thereby reducing the protein intake slightly to be closer to the RDI.

So there you have it! Putting my uni skills to the test in something functional and fun. Whether this was hard to grasp or not, the main take-away I’d give is simply to be mindful of your food intake and keeping up daily exercise, even if it’s a 30 minute walk. You need to expend more calories than the calories you consume to lose weight, and visa versa to gain weight. It might be interesting to track your food and exercise to see any patterns or differences, and to see if there’s anything you’d like to change or incorporate into it.

Until then, happy eating and exercising!


Australian Government 2006, Nutrient reference values for Australia and New Zealand: Including recommended dietary intakes, National Health and Medical Research Council.

Biolo, G., Agostini, F., Simunic, B., Sturma, M., Torelli, L., Preiser, J.C., Derby-Dupont, G., Magni, P., Strollo, F., Di Prampero, P., Guarnieri, G., Mekjavic, I.B., Pisot, R. & Narici, M.V. 2008, ‘Positive energy balance is associated with accelerated muscle athrophy and increased erythrocyte glutathione turnover during 5 wk of bed rest’, The American Journal of Clinical Nutrition, vol. 88, no. 4, pp. 950-958.

Carbone, J.W., Mcclung, J.P. & Pasiakos, S.M. 2012, ‘Skeletal muscle responses to negative energy balance: Effects of dietary protein’, Advances in Nutrition, vol. 3, no. 2, pp. 119-126.

Coates, J., Rogers, B.L., Blau, A., Lauer, J. & Roba, A. 2017, ‘Filling a dietary data gap? Validation of the adult male equivalent method of estimating individual nutrient intakes from household-level data in Ethiopia and Bangladesh’, Food Policy, vol. 72, pp. 27-42.

Fitzpatrick, T.B., Basset, G., Borel, P., Carrari, F. & DellaPenna, D. 2012, ‘Vitamin deficiencies in humans: Can plant science help?’, The Plant Cell, vol. 24, no. 2, pp. 395-414.

Government of South Australia 2017, Kilojoules explained, South Australia, viewed 3 October 2018, < rnet/healthy+living/healthy+eating/healthy+eating+tips/kilojoules+explained>

Guyenet, S.J. & Schwartz, M.W. 2012, ‘Regulation of food intake, energy balance, and body fat mass: Implications for the pathogenesis and treatment of obesity’, The Journal of Clinical Endocrinology & Metabolism, vol. 97, no. 3, pp. 745-755.

Janseens, P., Hursel, R., Martens, E. & Westerterp-Plantenga, M. 2013, ‘Acute effects of capsaicin on energy expenditure and fat oxidation in negative energy balance’, PLoS ONE, vol. 8, no. 7.

Prasad, R. 2012, ‘Micro mineral nutrient deficiencies in humans, animals and plants and their amelioration’, Proceedings of the National Academy of Sciences, India Section B: Biological Sciences, vol. 8, no. 2, pp. 225-233.

Tarnopolsky, M. 2008, ‘Building muscle: Nutrition to maximise bulk and strength adaptations to resistance exercise training’, European Journal of Sport Science, vol. 8, no. 2, pp. 67-76.

World Health Organization 2018, Obesity and Overweight, Geneva, viewed 3 October 2018, <>.