SummaryCurrent methods for assessment of food energy values are under pressure from a need for an internationally agreed method; remaining uncertainties in the composition, utilization and dietary effects of unavailable carbohydrate; the occurrence of new food ingredients; the application of new processing methods; the development of empirical approaches to food energy assessment and the potential for more functionally and biochemically based systems of assessment. Also, the experimental evaluation of alternative carbohydrates may be a tricky problem.