To compare temporal trends, over a 20-year period, in dietary habits between a county (Västerbotten) with a CVD prevention programme and a county (Norrbotten) without such a programme.

Cross-sectional data from the Northern Sweden MONICA study (survey period 1994, 1999, 2004, 2009 and 2014). Dietary habits were assessed by a semi-quantitative FFQ.

Counties of Norrbotten and Västerbotten, Northern Sweden.

Five thousand four hundred Swedish adults (mean age 56·9 years; 51·2 % women) from Västerbotten (47 %) and Norrbotten (53 %).

No differences in temporal trend for estimated percentage of energy intake from total carbohydrates, total fat, total protein and alcohol were observed between the counties (Pfor interaction ≥ 0·33). There were no between-county difference in temporal trends for overall diet quality (assessed by the Healthy Diet Score; Pfor interaction = 0·36). Nor were there any between-county differences for the intake of whole grain products, fruits, vegetables, fish, sweetened beverages or fried potatoes (Pfor interaction ≥ 0·09). Consumption of meat (Pfor interaction = 0·05) increased to a greater extent in Norrbotten from 2009 and onwards, mainly in men (sex-specific analyses, Pfor interaction = 0·04). Men in Västerbotten decreased their intake of sweets to a greater extent than men in Norrbotten (Pfor interaction < 0·01).

Over a 20-year period in northern Sweden, only small differences in dietary habits were observed in favour of a county with a CVD prevention programme compared with a county without such a programme.