A healthy diet is generally an ecologically sustainable one. Two 'win-win' guidelines may be given which deliver both health benefits and ecological benefits:
1. A less animal-based and more plant-based diet
2. The reduction of energy intake for those with an excessive body weight
The guideline ‘eat fish twice a week, including one portion of oily fish’ may yield health benefits, but may be ecologically detrimental.
There is a clear need for a deeper understanding of eco-friendly diet on which to base measures by which the environmental burden of food production and consumption can be reduced. The degree of uncertainty attached to these analyses deserves special attention.