To assess the overall diet quality of a sample of adolescents living in Alberta, Canada, and evaluate whether diet quality, nutrient intakes, meal behaviours (i.e. meal skipping and consuming meals away from home) and physical activity are related.

A cross-sectional study design. Students completed the self-administered Web-Survey of Physical Activity and Nutrition (Web-SPAN). Students were classified as having poor, average or superior diet quality based on Canada’s Food Guide to Healthy Eating (CFGHE).

One hundred and thirty-six schools (37 %) within forty-four public and private school boards (75 %) in Alberta, Canada.

Grade 7 to 10 Alberta students (n 4936) participated in the school-based research.

On average, students met macronutrient requirements; however, micronutrient and fibre intakes were suboptimal. Median CFGHE food group intakes were below recommendations. Those with poor diet quality (42 %) had lower intakes of protein, fibre and low-calorie beverages; higher intakes of carbohydrates, fat and Other Foods (e.g. foods containing mostly sugar, high-salt/fat foods, high-calorie beverages, low-calorie beverages and high-sugar/fat foods); a lower frequency of consuming breakfast and a higher frequency of consuming meals away from home; and a lower level of physical activity when compared with students with either average or superior diet quality.

Alberta adolescents were not meeting minimum CFGHE recommendations, and thus had suboptimal intakes and poor diet quality. Suboptimal nutritional intakes, meal behaviours and physical inactivity were all related to poor diet quality and reflect the need to target these health behaviours in order to improve diet quality and overall health and wellness.