Obesity rates are rising worldwide. According to the CDC, in the US, there has been a dramatic increase in obesity over the past 20 years. A similar phenomenon has been observed in other countries. Obesity related conditions (heart disease, stroke, diabetes, hypertension) are also increasing: around a third of adults in England now have prediabetes, and a tenth of US residents have diabetes, according to two News articles published on bmj.com this week.

Strategies to prevent and treat obesity include diet and exercise for most people, behavioral interventions for some, and bariatric surgery for a few. Recently, drugs agencies in the US and the EU approved several drugs for the treatment of obesity: orlistat is available worldwide, and phentermine and extended release topiramate, along with lorcaserin, are available in the United States, but not in the European Union.

This week, The BMJ published a Practice paper that summarizes the effectiveness and safety of these drugs, and provides practical advice on their use. By promoting weight loss, these drugs may have beneficial effects on health, but as the authors of the paper, Christian Rueda-Clausen and Raj Padwal, remind us, these drugs also have significant side effects, data on long term death and cardiovascular events are not available, and long term studies are needed.

Breast cancer is the most common cancer in women. Despite an increase in incidence, mortality from breast cancer has declined over the past couple of decades because of advances in diagnosis and treatment. Surgery (local or extensive) and radiotherapy are still cornerstones of treatment. However, recent advances in genetics and molecular biology allow targeted adjuvant chemotherapy and hormonal treatment, which is based on molecular stratification of tumors and leads to higher cure rates.

In a Clinical Review published in The BMJ this week, Belinda Yeo and her colleagues review the therapeutic options available to patients with different molecular subtypes of local and metastatic breast cancer. The promise of personalized medicine is becoming a reality for people with breast cancer.

Jose G. Merino is US clinical research editor, BMJ.