Comparison of protein intake per eating occasion, food sources of protein and general characteristics between community-dwelling older adults with a low and high protein intake

Abstract

Background & aims: Adequate protein intake is required to maintain muscle health in old age, but a low protein intake is very common in older adults. There is little insight in the general and dietary profile of older adults with a low protein intake. Therefore, this study aimed to compare community-dwelling older adults with a low and a high protein intake with regard to protein intake per eating occasion, food sources of protein and general participant characteristics.

Methods: Data were used from 727 Dutch community-dwelling older adults aged ≥70 years. Protein intake at meal and snack moments was measured with two non-consecutive dietary record assisted 24-h recalls. Low protein intake was defined as below the Recommended Dietary Allowance of 0.8 g protein per kg adjusted body weight per day (g/kg aBW/d). Differences in protein and food intakes between those with a low and a high protein intake were assessed with the Mann-Whitney U test and Chi-square test. Eating occasions were compared with regard to differences between the low and high protein intake group by using MANOVA. Characteristics of older adults with low protein intake were selected by using a multiple logistic backward elimination procedure.

Results: Low protein intake was present in 15% of the participants. At all eating occasions, median protein intake was lower in the low compared to the high protein intake group (breakfast, 7.8 vs. 10.8 g; lunch, 12.6 vs. 24.3 g; dinner, 21.8 vs. 31.1 g; snack moments, 6.7 vs. 9.7 g; P < 0.001), and was also consistently lower relative to energy intake. The contribution of animal protein to total protein intake was lower among the low protein intake group. Both groups obtained most protein from dairy, meat and cereals, but meat contributed less (21.5 vs. 28.2%) and cereals more (21.9 vs. 19.6%) among the low than the high protein intake group (all P < 0.01). Differences in protein intake, percentage of energy from protein and contribution of animal to total protein intake between the groups were largest at lunch compared to the other eating occasions. Out of a long list of variables, low protein intake was only associated with following a diet, being obese vs. normal-weight and drinking alcohol on none vs. some but <5 days/week (P < 0.05).

Conclusions: At all eating occasions, Dutch community-dwelling older adults with a protein intake <0.8 g/kg aBW/d ate less protein (also relative to their energy intake) and a lower proportion of animal protein compared to those with a high protein intake. These differences were largest at lunch. Major food sources of protein - in both groups - were dairy, meat and cereals. We could only identify following a diet, being obese and not drinking alcohol as general characteristics of older adults with a low protein intake.

Keywords: Ageing; Food sources; Meal moments; Protein intake; Protein intake distribution.