Reactive oxygen species (ROS) have important roles in health and disease, but are chemically complex and difficult to measure accurately. This consensus statement proposes guidelines and best practices on the nomenclature and assessment of ROS, oxidative reactions and oxidative damage in cells, tissues and in vivo.

Holst reflects on the development of GLP-1-based drugs for the therapy of obesity, from early observations to remarkable results in more recent clinical trials, discussing physiological, pharmacological and clinical considerations related to their use.

This authoritative Perspective lays a foundation for the field of obesity research by comparing commonalities and differences between competing models of obesity pathogenesis and by defining terms that are at the core of this discussion.

Veniant et al. report here on a GIPR antagonist conjugated to GLP-1 analogues that reduces body weight and improves metabolic markers in preclinical and phase 1 clinical settings.

Buglakova et al. present ¹³C-SpaceM, a method that combines stable isotope tracing with imaging mass spectrometry thus enabling spatial analysis of lipid dynamics with near-single-cell resolution in tissues.

Sukka et al. delineate a metabolic pathway in macrophages that involves tryptophan uptake and metabolism to drive efferocytosis and subsequent resolution in the context of inflammation.

Administration of exogenous mitochondria from mice or humans, or stimulation of mitochondria transfer from haematopoietic cells through bone marrow transplant from wild-type mice, is shown to improve morbidity and mortality in a mouse model of the mitochondrial disease Leigh syndrome.

Grankvist et al. combine global isotopic tracing and metabolic flux modelling to characterize metabolic networks in human intact liver tissue.

Qiu et al. provide insight into the metabolic adaptations that enable breast cancer cells to proliferate in the face of glutaminolysis blockade.

Pancreatic islet β-cells can regulate insulin secretion in vivo, even in the absence of non-β-cells.

Although Western societies are mesmerized by the power of new anti-obesity drugs, we must not forget how diet can affect metabolic outcomes. In this Focus issue, and accompanying web collection, we showcase a series of Reviews, Comments and original research articles that present up-to-date evidence on how dietary interventions can affect cardiometabolic health.

Extracellular vesicles (EVs) are now recognized as powerful modulators of metabolism, and thus the new field of EV-mediated metabolic regulation is growing exponentially. Here, we discuss special experimental considerations for the study of EV function in metabolism.

Despite the high utility and widespread use of Cre driver lines, lack of Cre specificity, Cre-induced toxicity or poor experimental design can affect experimental results and conclusions. Such pitfalls must be considered before embarking on any Cre-based studies in metabolic research.

Time-restricted eating has become a popular diet for weight management and has spurred tremendous interest in the scientific community. The translation of results from TRE trials heavily depends on trial design. In this Comment, we provide general guidelines on optimizing the design and performance of time-restricted eating trials in human participants.