They have undergone industrial processes like hydrogenation and moulding, and contain additives like dyes, stabilizers, flavor enhancers, emulsifiers, and de-foaming agents.

Their ingredients tend to make them sugary or salty, often high in saturated fats or trans-fats, and depleted in dietary fiber and various micronutrients and other bioactive compounds.

Are often formulated to be hyperpalatable, which makes it hard to make healthy choices and to avoid overconsumption.

Can sometimes be marketed falsely as healthy. For example, by the addition of dietary fiber and some micronutrients; the replacement of sugar by artificial sweeteners; or the reduction of sodium, enabling manufacturers to make health claims despite the product remaining unhealthy.

Are very common. Recent studies estimate 73% of the US food supply to be ultra processed e.g. Ravandi et al. 2022.