Which of the following statements relating to leptin and the metabolism of lipids is correct. (Select all that apply.) Leptin acts mainly in the brain to stimulate appetite. High levels of leptin are interpreted as overfeeding. Insulin stimulates production of leptin in adipocytes. Leptin is a hormone involved in short-term control of eating behaviour. Higher leptin levels result in a decrease in appetite.

High levels of leptin are interpreted as overfeeding.

Insulin stimulates production of leptin in adipocytes.  

Higher leptin levels result in a decrease in appetite.

Explanation:

Leptin is a peptide hormone that helps to control body weight. This hormone (leptin) is synthesized by fat cells (i.e., adipocytes), then circulates in the blood and goes to the brain, in particular in a region of the brain called the hypothalamus, where it acts to alter food intake over the long term. Higher leptin levels trigger the hypothalamus to lower the appetite. Insulin is another peptide hormone that acts to regulate long-term leptin secretion of adipose cells through a posttranscriptional mechanism. In turn, leptin increases insulin sensitivity, thereby both hormones regulate each other. When body fat decreases as a consequence of decreased appetite, insulin and leptin concentrations in the bloodstream also decrease.

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