А как вам такие "составляющие диеты/рациона":
Weight, midarm circumference, triceps skinfold thickness, arm muscle circumference, albumin, prealbumin, transferrin and total lymphocyte count were measured at each outpatient visit in patients reveiving home parenteral nutrition from September 1987 to November 1991. Each nutritional variable was analysed for individuals and for the whole group.
https://www.sciencedirect.com/science/article/abs/pii/026156...Maternal smoking as a nutritional variable
https://www.tandfonline.com/doi/abs/10.1080/03670244.1978.99...Вот здесь это действительно компоненты рациона питания:
To date, suitable quantitative biomarkers have been available for few diet components (e.g. total energy, protein, potassium, sodium) and physical activity (AREE). ...To use these profiles to calculate intake values for each nutritional variable for which a biomarker is established
https://maps.cancer.gov/overview/DCCPSGrants/abstract.jsp?ap...Т.е. надо внимательно смотреть контекст
ну и одно из значений фактора питания
https://dic.academic.ru/dic.nsf/enc_medicine/32330/Фа́ктор