On a country and diet basis, you can use the WWF model to set the amount of different food groups in a diet and see the caloric, mortality and environmental impacts of the new diet if adopted by the entire country.
The model takes previously published figures as its basis for the mortality and environmental impacts, and national dietary guidelines to give recommended caloric intakes from each food group. The user can adjust intakes of 13 traditional food groups (e.g. grains, poultry, alcohol), with guidance on what an appropriate caloric intake from each food group would be. The model also has presets for common dietary scenarios, such as observing national food guidelines, vegetarian populations and so on.
As outputs, the model gives estimates of environmental impacts, such as greenhouse gas emissions and land-use, broken down by food group. An estimated percentage change in overall mortality rate is also shown. Finally, the model also gives some examples of what a weekly shopping basket might look like for the defined diet.
While being very user-friendly and displaying a large amount of information in an accessible manner, the model has some limitations. Foremost is its use of calories as the only indicator of nutrition. While sufficient energy intake is required, often micronutrients are the limiting factor in the adequacy of a diet, and these are not included in the model. Anyone using the model to compare diets must bear this vital element in mind.
The DELTA Model takes a different view of the impacts of food, assessing whether global food production is nutritionally adequate for the global population. The individual, national and global perspectives are all important in the consideration of sustainable food, and each should be modelled accordingly.