This study aims to develop a new methodology for calculating the economic costs of unhealthy diets, to improve on current methodologies. It utilizes relatively new, holistic, measures of diet quality. Following development of the methodology, we test it out using cross-country data from public sources, including one of the new more holistic measures of diet quality, the Global Dietary Recommendations Score (GDRS) which are publicly available. We examine whether the GDRS is significantly associated with measures of overweight and obesity, or with NCD risk factors (hypertension and diabetes). These other data are also publicly available from sources such as UNICEF, FAO and WHO. The results are promising, although there are limitations in using cross-country data, and we plan next to do similar analysis using a slightly different diet quality metric, within one or more countries.