Food and nutrition are fundamental to military capability. Historical examples demonstrate that a failure to supply adequate nutrition to armies inevitably leads to disaster; however, innovative measures to overcome difficulties in feeding reap benefits, and save lives. In barracks, UK Armed Forces are currently fed according to the relatively new Pay As You Dine policy, which has attracted criticism from some quarters. The recently introduced Multi-Climate Ration has been developed specifically to deal with issues arising from Iraq and the current conflict in Afghanistan. Severely wounded military personnel are likely to lose a significant amount of their muscle mass, in spite of the best medical care. Nutritional support is unable to prevent this, but can ameliorate the effects of the catabolic process. Measuring and quantifying nutritional status during critical illness is difficult. A consensus is beginning to emerge from studies investigating the effects of nutritional interventions on how, what and when to feed patients with critical illness. The Ministry of Defence is currently undertaking research to address specific concerns related to nutrition as well as seeking to promote healthy eating in military personnel.