Phelan · Obesity (Silver Spring, Md.) 2006 · prospective cohort study · n=2708

Are the eating and exercise habits of successful weight losers changing?

Cited 116 times in the scientific literature.

Level 3 - non-randomized controlled study

Prospective observational cohort study

PubMed 16741274 · doi:10.1038/oby.2006.81 · record verified 2026-08-27

What was done

Researchers evaluated temporal shifts in diet and physical activity among 2,708 successful weight losers enrolling in the National Weight Control Registry (NWCR) across intermittent years from 1995 to 2003. Enrollees had lost an average of 33.1 kg and maintained at least a 13.6-kg loss for an average of 5.8 years prior to entry. Dietary intake and physical activity were measured at registry enrollment and prospectively tracked over 1 year.

What was found

Between 1995 and 2003, daily energy intake from fat increased from 23.8% to 29.4%, saturated fat intake was reported to shift from 12.3 to 154.0 g/d, and calories from carbohydrate decreased from 56.0% to 49.3% (all p < 0.0001). The proportion of enrollees consuming a low-carbohydrate diet (<90 g/day) increased from 5.9% to 17.1% (p = 0.0001). Physical activity was 3,316 kcal/week in 1995 and averaged 2,620 kcal/week in later cohorts. Across all cohorts, 1-year weight regain was significantly associated with higher total caloric intake, higher fat intake, greater fast food consumption, and lower physical activity (p < 0.03).

Why it matters

Even as popular dietary trends drove modest increases in fat and low-carbohydrate adoption among successful weight losers, the core behavioral determinants of long-term weight maintenance—calorie control, moderate fat intake, minimal fast food, and high activity levels—remained consistent.

Limits

The study relies on self-reported dietary and exercise data in a self-selected registry cohort, which limits generalizability to the broader population attempting weight loss. The abstract also reports an apparent typographical error in saturated fat intake (increasing to 154.0 g/d).

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