Table 3.

Relative odds of weight gain (≥10 % from baseline weight v. <10 %) by quintile (Q) of adherence to a low-fat, reduced-carbohydrate, Mediterranean-style or Dietary Guidelines for Americans (DGA) diet pattern among postmenopausal women who participated in the Women’s Health Initiative Observational Study^* (Odds ratios and 95 % confidence intervals)

	Unadjusted (n 88 714)		Adjusted (n 70 177)
	OR	95 % CI	OR	95 % CI
Low-fat diet
Q1 (high adherence)	0·86	0·82, 0·91	1·43	1·33, 1·54
Q2	0·77	0·73, 0·81	1·14	1·06, 1·22
Q3	0·79	0·74, 0·84	1·05	0·97, 1·13
Q5	0·83	0·78, 0·89	0·99	0·93, 1·07
Q5 (low adherence)	1·00	Ref.	1·00	Ref.
Ptrend†	<0·001		<0·001
Reduced-carbohydrate diet
Q1 (high adherence)	1·05	1·00, 1·11	0·71	0·66, 0·76
Q2	0·92	0·88, 0·97	0·71	0·67, 0·76
Q3	0·89	0·85, 0·93	0·77	0·73, 0·82
Q5	0·91	0·87, 0·95	0·84	0·80, 0·88
Q5 (low adherence)	1·00	Ref.	1·00	Ref.
Ptrend†	0·516		<0·001
Mediterranean-style diet
Q1 (low adherence)	1·00	Ref.	1·00	Ref.
Q2	0·89	0·85, 0·93	0·99	0·94, 1·05
Q3	0·85	0·81, 0·89	1·01	0·96, 1·07
Q5	0·78	0·74, 0·82	1·00	0·94, 1·07
Q5 (high adherence)	0·68	0·64, 0·73	0·95	0·88, 1·03
Ptrend†	<0·001		0·513
DGA diet
Q1 (low adherence)	1·00	Ref.	1·00	Ref.
Q2	0·89	0·84, 0·94	1·04	0·97, 1·11
Q3	0·82	0·78, 0·87	1·07	1·00, 1·14
Q5	0·80	0·76, 0·84	1·14	1·07, 1·22
Q5 (high adherence)	0·77	0·73, 0·81	1·24	1·15, 1·33
Ptrend†		<0·001		<0·001

Ref., referent values.

^*All adjusted models controlled for baseline total energy intake (continuous), diet pattern at year 3 of follow-up, age (continuous), baseline total mild, moderate and hard physical activity as metabolic equivalents of task-h/week, race/ethnicity, annual family income and baseline smoking status. All categorical variables (race/ethnicity, annual family income and baseline smoking status) were modeled using disjoint indicator variables.

^†P_trend corresponds to a Wald test statistic when a linear term for quintile of diet pattern was substituted in the model.