Table 3.

 Combined low risk lifestyle factors and risk of gestational diabetes in 20 136 pregnancies in Nurses’ Health Study II

Low risk group	Percentage of pregnancies	No of pregnancies with gestational diabetes	Relative risk* (95% CI)	Population attributable risk percentage† (95% CI)
3 factors in low risk category (current non-smoker, moderate/vigorous physical activity ≥150 min/week, healthy eating‡)	20.3	112	0.59 (0.48 to 0.71)	35.4 (25.1 to 44.9)
All 4 factors in low risk category (BMI <25.0, current non-smoker, moderate/vigorous physical activity ≥150 min/week, healthy eating‡)	16.3	71	0.48 (0.38 to 0.61)	47.5 (35.6 to 56.6)

*Estimated from generalized estimating equation models and adjusted for age, parity, family history of diabetes, history of infertility, race/ethnicity, questionnaire period, total energy intake, and alcohol intake. Reference group for relative risk is all other pregnancies not in low risk group as defined in table.

†Percentage of cases of gestational diabetes in population theoretically attributable to non-adherence to particular factors.

‡Alternate Healthy Eating Index-2010 diet score in upper two fifths.