Food Portion Size Estimation for Developing a Healthy Eating Index: Influence of Unit Count and Energy Density

¹ Faculty of Public Health, Universitas Diponegoro, Jl. Prof Jacub Rais Kampus UNDIP Tembalang, Semarang, Indonesia 50275
² Vocational School, Universitas Diponegoro, Jl. Gubernur Mochtar, Tembalang, Kec. Tembalang, Kota Semarang, Jawa Tengah 50275

^* Corresponding author: alfifairuzasna@lecturer.undip.ac.id

Abstract

Estimating food consumption is often influenced by the intricate cognitive processes involved in determining portion sizes. Understanding the factors influencing these processes can enhance the accuracy of dietary assessments. This study aims to evaluate the ability of participants to estimate portion sizes of common foods and to identify estimation errors. Methods: This study used a cross-sectional approach involving 35 participants, who estimated the portions of various foods, measured in grams or milliliters, based on memory. The magnitude and direction of estimation errors were analyzed. Underestimation was defined as estimated quantities (EQ) less than 90% of the actual weighed quantity (WQ), while overestimation was defined as EQ greater than 110% of the WQ. Results: Only 15.59% of the estimates were considered accurate (approximately 10% of the actual weight). Animal proteins, vegetables, and sugars were the most frequently underestimated, while staple foods, vegetable proteins, fruits, vegetables, and fats/oils were the most commonly overestimated. Conclusion: This study revealed a low proportion of accurate food portion size estimates, with a tendency to overestimate low-energy foods and underestimate high-energy foods.