Background: In primary care encounters, it is unknown whether physician advice on weight-related matters leads to patient weight loss. To examine this issue, we analyzed physician weight loss advice and measured corresponding changes in patients' dietary intake, physical activity, and weight.
Methods: Using audio-recorded primary care encounters between 40 physicians and 461 of their overweight or obese patients, we coded weight-related advice as nonspecific, specific nutritional, specific exercise, or specific weight. Physicians and patients were told the study was about preventive health, not weight. We used mixed models (SAS ProcMixed), controlled for physician clustering and baseline covariates, to assess changes in diet, exercise, and measured weight, both pre-encounter and 3 months post-encounter.
Results: When discussing weight, physicians typically provided a combination of specific weight, nutrition, and physical activity advice to their patients (34%). Combined advice resulted in patients reducing their dietary fat intake (P=.02). However, when physicians provided physical activity advice only, patients were significantly (P=.02) more likely to gain weight (+1.41 kg) compared with those who received no advice.
Conclusion: When giving weight-related advice, most physicians provided a combination of lifestyle recommendations. Combining advice may help patients reduce their fat intake. Physical activity advice alone may not be particularly helpful.