Larger animals tend be more intelligent just because they have larger brains, so their sufferings will be more complex: they may understand their fate in advance. I think whales and elephants are close to this threshold.
An opposite logic may be valid: we should eat animals with smallest brains as their suffering will be less complex and also each of them is less individual and more like a copy of one another. Here we assume that suffering of two copies is less than of two different minds.
Larger animals tend be more intelligent just because they have larger brains, so their sufferings will be more complex: they may understand their fate in advance. I think whales and elephants are close to this threshold.
An opposite logic may be valid: we should eat animals with smallest brains as their suffering will be less complex and also each of them is less individual and more like a copy of one another. Here we assume that suffering of two copies is less than of two different minds.