Overweight Seniors Require Exercise AND Dietary Control

Ask an overweight or obese senior what they should be doing to improve their health, and you’ll get a variety of answers.  Only rarely will you get the reply: “Exercise and eat right!” More often it’s one or the other, or a third option (e.g. “watch less TV”).  Now a study reported in the New England Journal of Medicine has clarified the situation – you need to exercise AND eat right. 

This was a randomized, prospective, well-controlled trial, which gives the findings a high level of legitimacy.  The participants were obese adults aged 65 or older.  They were randomly allocated to a control group, a weight management (diet) group, an exercise group, or a diet-plus-exercise group, for one year.  The main criterion of effect was improvement on the Physical Performance Test score.  Secondary measures of improvement were improvement in frailty, body composition, bone mineral density, and quality-of-life scores. The weight control groups had a balanced diet that cut 500 to 750 calories from individual daily requirements, aiming at a 10% loss of baseline weight by 6 months.  The exercise groups required three group-exercise training sessions a week, including aerobic, resistance, flexibility and balance training.   

Of the 107 enrolled participants, 93 completed the 1-year study.  An intent-to-treat analysis was done, being considered the most relevant analysis for translating results to the ‘real world’.  The Physical Performance Test scores were increased by 5.4 points in the diet-plus-exercise group, by 3.4 points in the diet group, and by 4.0 points in the exercise group, compared with the control group.  A difference of 1.7 points between group averages is considered meaningful.  Body weight fell by 10% in the diet group and by 9% in the diet-plus-exercise group, but was unchanged in the other two groups.  However, in the exercise group lean body mass increased as fat mass decreased; in the diet and diet-plus-exercise groups, both lean body mass and fat mass decreased.  Bone mineral density at the hip decreased 1% in the diet-plus-exercise group and 3% in the diet group, but increased by 1.5% in the exercise group.  The quality-of-life measurement improved in all three intervention groups.

These results would be most satisfactory if they could be guaranteed across all populations of seniors.  It’s not clear, though, if they could be extrapolated to other groups; the participants in this study were mostly white, women, well-educated, and motivated to lose weight. Nevertheless, one must conclude that calorie reduction plus a physical training program offers the best weight-loss opportunity for obese people over 65, and is clearly better than either intervention alone.