Obesity and weight loss alter serum polyunsaturated lipids in humans.

Serum ω6 (n−6) fatty acids were assessed in 12 obese women during an outpatient very-low calorie diet (VLCD). Ten subjects (S10) achieved a mean weight loss of 17 kg over 3−5 mo (initial weight-for-height 157%). Serum was obtained before (baseline) and monthly during the VLCd and from five of them (S5) after 2−3 mo of weight stability (refed) at 21 kg of loss. At baseline for S10, the serum phospholipid (PL) 20: 4ω6 was 9.16 wt% and differed from normal (12.81 wt%) by P < 0.0001, but cholesterol ester (CE) 20:4ω6 did not differ from normal. During 3 mo of VLCD, the S10 serum PL and CE 18:2ω6 fell (P < 0.005 and 0.0001, respectively)