Dietary intake of polyunsaturated fatty acids (PUFAs) or saturated fatty acids (SFAs) differently modulates neurophysiological and behavioral functions in response to altered hypothalamic-pituitary-adrenal (HPA)-axis activity and an individual's development. In this context, an individual's social environment, including social interactions and social hierarchies, is closely related to hormone concentrations and possibly interacts with dietary fatty acid effects. We investigated if dietary supplementation with walnut oil (high in PUFAs) and coconut fat (high in SFAs), compared to a control group, affects body mass gain, cortisol and testosterone concentrations, plasma fatty acids, and social behavior in male domestic guinea pigs from adolescence to adulthood. For analyses of cortisol and testosterone concentrations, social interactions were included as covariates in order to consider effects of social behavior on hormone concentrations. Our results revealed that SFAs increased escalated conflicts like fights and stimulated cortisol and testosterone concentrations, which limited body mass gain and first-year survival. PUFAs did not remarkably affect social behavior and hormone concentrations, but enabled the strongest body mass gain, which probably resulted from an energetic advantage. Neither sociopositive nor agonistic behaviors explained age-specific differences in hormone concentrations between groups. However, a high number of subdominant individuals and lower testosterone concentrations were related to increased cortisol concentrations in adult PUFA males. Our findings demonstrate the importance of dietary fatty acids regarding behavioral and endocrine developmental processes and adaptations to the social environment by modulating HPA-axis function and body homeostasis.

饮食中多不饱和脂肪酸（PUFA）或饱和脂肪酸（SFA）的摄入会不同程度地调节下丘脑-垂体-肾上腺（HPA）轴活性和个体发育，从而调节神经生理和行为功能。在这种情况下，一个人的社会环境，包括社会互动和社会等级制度，与荷尔蒙浓度密切相关，并可能与饮食中的脂肪酸效应相互作用。我们调查了与对照组相比，膳食补充核桃油（PUFAs含量高）和椰子脂（SFAs含量高）是否会影响雄性豚鼠的体重增加，皮质醇和睾丸激素浓度，血浆脂肪酸以及社会行为从青春期到成年。为了分析皮质醇和睾丸激素的浓度，社会互动作为协变量包括在内，以考虑社会行为对激素浓度的影响。我们的结果表明，SFA加剧了诸如战斗之类的升级冲突，并刺激了皮质醇和睾丸激素的浓度，从而限制了体重增加和第一年生存。PUFA不会显着影响社交行为和激素浓度，但可以带来最大的体重增加，这可能是由于精力充沛的优势所致。社会阳性和激动行为均不能解释两组之间激素浓度的年龄差异。但是，大量的主要个体和较低的睾丸激素浓度与成年PUFA男性皮质醇浓度升高有关。