Nutrient Intake During Diet-Induced Weight Loss and Exercise Interventions in a Randomized Trial in Older Overweight and Obese Adults.

ABSTRACT

OBJECTIVES: Dietary restriction in obese older adults undergoing weight loss may exacerbate nutrient deficiencies common in this group; the nutritional health of older adults is a factor in their quality of life, disability, and mortality. This study examined the effect of an 18-month weight loss program based in social cognitive theory incorporating partial meal replacements, on nutrient intake in older overweight and obese adults. DESIGN: The following analysis is from the Intensive Diet and Exercise for Arthritis (IDEA) trial, a single-blind, randomized controlled trial. Individuals were randomized into one of three 18-month interventions: exercise (E); intensive diet-induced weight loss (D); or intensive diet-induced weight loss plus exercise (D+E). SETTING: The study setting was at a university research facility. PARTICIPANTS: Overweight and obese older adults (n=388; BMI=33.7±3.8 kg/m2; 65.8±6.1 years) were recruited. INTERVENTIONS: The D and D+E interventions (group mean goal of ≥10% loss by 18-months) utilized partial meal replacements (2 meal replacement shakes/day for 6-months). Exercise training for E and D+E was 3 days/week, 60 minutes/day. MEASUREMENTS Three day food records were collected at baseline, 6-months, and 18-months and analyzed for total energy and macro- and micronutrient intake. Comparisons of dietary intake among treatment groups were performed at 6 and 18 months using mixed linear models. RESULTS: Weight loss at 18-months was 11.3±8.3% (D), 10.3±6.8% (D+E), and 1.2±4.2% (E). Meal replacements were used by more than 60% (6-months) and 50% (18-months) of D and D+E participants, compared to ≤15% for E. Both D and D+E consumed less energy and fat, and more carbohydrates and selected micronutrients than E during follow-up. More than 50% of all participants consumed less than the recommended intake of particular vitamins and minerals. CONCLUSIONS: The diet intervention improved intakes of several nutrients. However, inadequate intake of several vitamins and minerals of concern for older adults suggests they need further guidance to assure adequate intake.