Health claims on food products are often used as a means to highlight scientifically proven health benefits associated with consuming those foods. But do consumers understand and trust health claims? This paper provides an overview of recent research on consumers and health claims including attitudes, understanding and purchasing behaviour. A majority of studies investigated selective product-claim combinations, with ambiguous findings apart from consumers' self-reported generic interest in health claims. There are clear indications that consumer responses differ substantially according to the nature of carrier product, the type of health claim, functional ingredient used or a combination of these components. Health claims tend to be perceived more positively when linked to a product with an overall positive health image, whereas some studies demonstrate higher perceived credibility of products with general health claims (e.g. omega-3 and brain development) compared to disease risk reduction claims (e.g. bioactive peptides to reduce risk of heart disease), others report the opposite. Inconsistent evidence also exists on the correlation between having a positive attitude towards products with health claims and purchase intentions. Familiarity with the functional ingredient and/or its claimed health effect seems to result in a more favourable evaluation. Better nutritional knowledge, however, does not automatically lead to a positive attitude towards products carrying health messages. Legislation in the European Union requires that the claim is understood by the average consumer. As most studies on consumers' understanding of health claims are based on subjective understanding, this remains an area for more investigation.