Total individual macronutrient intake is a member of the class of indicators that measure individual intake of nutrients. It quantifies the percentage of caloric intake from the three major macronutrient groups – protein, fats, and carbohydrates. These three nutrients have distinct and important functions in the body, and all are necessary for proper growth, development and cognitive and physical functioning. Both undernutrition and overnutrition due to improper macronutrient intake, and the related health complications, continue to be a major health concern in the developing world (Muller & Krawinkel, 2005). Other indicators included in the Guiding Framework that measure individual nutrient intake include Mean Adequacy Ratio (MAR), total individual micronutrient intake, and total individual energy intake. For more discussion on the comparative uses of these indicators, refer to the “Uses” section below.
Method of Construction
In order to estimate an individual’s caloric intake from the three macronutrients, survey data must be collected from a quantitative 24-hour dietary recall or a weighed food record (WFR). Population mean consumption can be estimated with a single survey, but the survey must be repeated on at least a subsample of the survey population for two non-consecutive days of intake to estimate “usual intake” (IOM, 2000). This should be completed in a way such that the final sample is representative of all days of the week. Using a Food Composition Table (FCT) and the weight (grams) of the foods consumed, an estimate of the amount of protein, fat, and carbohydrates consumed per subject is calculated (distinguishing between fiber and other forms of carbohydrates). The total grams of each macronutrient are added together, and the caloric value of each is calculated using the following equation:
Calories(Kcal) = [Protein(g)*4] + [Fats(g)*9] + [Av. Carbohydrates(g)*4] + [Fiber(g)*2 ] + [Alcohol(g)∗7]
*Note in this equation, Total Carbohydrates = [Available Carbohydrates + Fiber]
Finally, the proportion of calories from each macronutrient is calculated by dividing the calories from each by the total calories consumed. For more information on calculating this indicator, refer to the first method discussed in the “New Methods Considered” section of the following paper published in the Journal of Food Composition and Analysis (Schakel et al., 2009).
Individual macronutrient intake is a useful indicator for understanding the dietary intake and quality of population subgroups, such as pregnant and lactating women, and for understanding the allocation of food resources among household members (Ferro-Luzzi, 2002). These data can also contextualize shifting diet composition that has been observed in conjunction with demographic and economic transition in low- and middle-income countries, as individuals consume higher percentage of their calories from fat (Popkin, 2001). Additionally, information on the food source of the macronutrients is lost, and if there are particular food groups of interest or priority, an indicator like overall dietary pattern may be of more use, as percent of energy consumed is reported in terms of food group, as opposed to nutrient. Finally, since this indicator does not include information on micronutrient intake, it is not useful for capturing a full picture of dietary quality. More inclusive indicators such as MAR or probability of inadequacy are more appropriate for using individual nutrient intake data to provide a picture of the diet as a whole.
Strengths and Weaknesses
One advantage of this indicator is that it allows researchers to estimate an individual’s intake of specific macronutrients without conducting expensive and technically complex biomarker analyses that might otherwise be necessary in order to quantify intake (Hedrick et al., 2012). Also, in gathering data on individual intake, researchers would be able to pair findings with individual health outcomes or demographic information, such as religion, age, sex, education, or any other characteristics of interest, assuming the study has been designed for these purposes (Ferro-Luzzi, 2002). However, a weakness of this indicator is that it does not speak to the adequacy of the diet as a whole, the ability of individuals to absorb and use the nutrients, or if intake levels are adequate and healthy, as other anthropometric data are necessary for this assessment (Institute of Medicine, 2000).
Intake data can be obtained from individual weighed food records or quantitative 24-hour dietary recall surveys. National or regional Food Composition Tables should be used to identify the nutrient contents of the foods and can be found at Food and Agriculture’s (FAO) International Network of Food Data Systems (INFOODS) or the International Life Science Institute’s (ILSI) CatFCDB. RDAs can be obtained from the Institute of Medicine (Institute of Medicine, 2006).