Today's chickens may be fatter than in previous generations

There is debate about whether modern chicken contains more fat than chicken did in previous decades. This might explain why chicken isn't always found to be much healthier than beef (Vergnaud et al., 2010, Maki et al., 2012). It could be that chicken used to be a health food but now has been altered to be less healthy.

There are 3 possible mechanisms from this:

• We have genetically selected much fattier varieties
• They have ended up fattier through genetic selection, but were not specifically selected for fattiness (e.g. fattiness increases disease resistance or reduces aggression or is a consequence of higher body weight)
• We feed them a diet that makes them

Evidence for

Havenstein found that 2001 broilers had higher levels of fat per 100g weight than 1957 broilers^[1]

Some studies showed that today’s poultry meat contains higher lipid content compared with that produced some years ago (Wang et al., 2009; Crawford et al., 2010; Kuttappan et al., 2012a).^[2]

White striping

White striping is a muscular condition where the breasts of chickens have white stripes of fat in them. This also causes the breast to have an undesirable texture, and so white striped meat is considered low quality. It is caused by growing chickens too fast. Kuttappan et al. (2012a) found that white-striped fillets had a higher fat content and lower protein content compared with normal fillets. Petracci et al. (2014) showed that severe white-striped fillets had a higher total energy content than normal fillets, while the contribution of energy from fat was increased about three-fold.^[3]

Evidence against

A study in the United Kingdom (Fleming et al., 2007) which compared birds from three modern genetic lines with their 1972 control lines and showed at typical slaughter ages and similar body weights that the modern birds had considerably lower carcass fat contents (13.9 to 15.4 v. 21.6 to 23.8 g/100 g; excluding abdominal fat pad).

This study^[4] shows that abdominal fat has increased slower than total body mass in chickens over the past 80 or so years. This might suggest that the % of an entire chicken that is fat might not be higher in modern birds than before. However they only measured abdominal fat, so other areas of the chicken could be fattier.

References