Table 1.

Human intervention studies comparing the effect of SFA and PUFA on liver steatosis

Subjects	Intervention	Duration	Body weight	Liver fat	Other observations	Reference
39 healthy men and women age: 20–38 y BMI: 18–27 kg m2	Randomized control study; overfeeding (+750 kcal per day) SFA (palmitate, 16:0)) or PUFA (linoleate 18:2 n‐6)) muffins. (Muffins were added to the habitual diet).	7 weeks	SFA: 1.6 kg ↑ PUFA: 1.6 kg ↑	SFA ↑ PUFA ↔	SFA: larger increase in visceral adipose tissue compared with PUFA PUFA: increase in lean tissue	[14]
60 healthy men and women Age: 20–55y BMI: 25–32 kg m2	Randomized control study; overfeeding (+700 kcal per day) SFA (palmitate, 16:0)) or PUFA (linoleate 18:2 n‐6)) muffins. (Muffins were added to the habitual diet).	8 weeks	SFA: 2.3 kg ↑ PUFA: 2.6 kg ↑	SFA ↑ PUFA ↔	SFA: increased serum ceramides PUFA: reduced serum ceramides. No changes in markers of inflammation, oxidative stress or endothelial function.	[15]
67 men and women with and without T2D Age: 30–65 y BMI: ≈30 kg m2	Randomized control study; diet high in SFA (butter) or PUFA (linoleate; ≈6.7 E%) intake. Modest increase in total energy intake (PUFA: +138 kcal per day; SFA: + 225 kcal per day).	10 weeks	SFA: 0.8 kg ↑ PUFA: 0.4 kg↑	SFA ↑ PUFA ↓	Modest increase in inflammatory markers after SFA compared with PUFA. No difference in oxidative stress markers between the diets.	[16]
39 healthy men and women age: 18–65 y BMI: 27–35 kg m2	Randomized control study; overfeeding (+1000 kcal per day). SFA or UFA (MUFA and PUFA).	3 weeks	SFA: 1.4 kg ↑ PUFA: 0.9 kg↑	SFA ↑↑ UFA ↑	Increase in insulin resistance (clamp) and circulating ceramides in SFA.	[17]

Only studies are selected in which treatment groups within studies are similar in energy intake and macronutrient content. Abbreviations: y: year; BMI: body mass index; kg: kilogram; m: meter; kcal: kilocalories: SFA: saturated fatty acids; PUFA: poly‐unsaturated fatty acids.