<jats:title>Abstract</jats:title><jats:p>When organisms are unable to feed <jats:italic>ad libitum</jats:italic> they may be more susceptible to negative effects of environmental stressors such as ocean acidification and warming (OAW). We reared sea bass (<jats:italic>Dicentrarchus labrax</jats:italic>) at 15 or 20 °C and at ambient or high <jats:italic>P</jats:italic>CO<jats:sub>2</jats:sub> (650 versus 1750 µatm <jats:italic>P</jats:italic>CO<jats:sub>2</jats:sub>; pH = 8.1 or 7.6) at <jats:italic>ad libitum</jats:italic> feeding and observed no discernible effect of <jats:italic>P</jats:italic>CO<jats:sub>2</jats:sub> on the size-at-age of juveniles after 277 (20 °C) and 367 (15 °C) days. Feeding trials were then conducted including a restricted ration (25% <jats:italic>ad libitum</jats:italic>). At 15 °C, growth rate increased with ration but was unaffected by <jats:italic>P</jats:italic>CO<jats:sub>2.</jats:sub> At 20 °C, acidification and warming acted antagonistically and low feeding level enhanced <jats:italic>P</jats:italic>CO<jats:sub>2</jats:sub> effects. Differences in growth were not merely a consequence of lower food intake but also linked to changes in digestive efficiency. The specific activity of digestive enzymes (amylase, trypsin, phosphatase alkaline and aminopeptidase N) at 20 °C was lower at the higher <jats:italic>P</jats:italic>CO<jats:sub>2</jats:sub> level. Our study highlights the importance of incorporating restricted feeding into experimental designs examining OAW and suggests that <jats:italic>ad libitum</jats:italic> feeding used in the majority of the studies to date may not have been suitable to detect impacts of ecological significance.</jats:p>