Identical twins join a scientific study and must stick to either a plant-based or omnivorous diet for eight weeks to determine what is the healthiest.

The twins begin their diets with a mix of successes and struggles. The recommended dietary guidelines raise concerns. A renowned chef changes course.

The twins adjust to cooking their own meals. With some animal products linked to health problems, innovators turn to plants for sustainable alternatives.

The study results are revealed to the twins as they review their weight, gut and brain health, and more. A movement in the food industry gains momentum.