Introduction

Cardiovascular disease (CVD) is a leading cause of death in low-, middle-, and high-income countries, accounting for a quarter of deaths globally in 2001 [1]. Until recently most of our knowledge concerning etiological risk factors for CVD focused on adulthood. Indeed, there is good evidence that major adult risk factors such as smoking, diet, physical activity, hypertension, and obesity explain much of the variation in geographical and secular trends of CVD incidence and it has been suggested that there is no need to investigate further [2]. However, it has also been known for decades that the pathophysiological process of atherosclerosis begins in childhood and young adulthood [3,4]. Obesity and other cardiovascular risk factors such as hyperlipidemia, high blood pressure, and insulin resistance are present in childhood and track into adulthood [5–8], and a growing body of evidence has consistently shown associations of obesity in childhood and adolescence with mortality and cardiovascular morbidity later in life [9]. The adverse consequences of childhood obesity are not limited to the cardiovascular system, indeed it can affect almost every organ system and has other serious complications such as diabetes, fatty liver, asthma, and may have psychosocial complications as well [10].

In both the USA and in England approximately one in five women of reproductive age is now obese [11,12]. This increasing prevalence of overweight and obesity among women of childbearing age is a growing concern, since, as reviewed in Chapters 5, 8, and 16, obesity in pregnancy is associated with increased risk of most pregnancy complications, such as gestational diabetes mellitus (GDM), hypertensive disorders of pregnancy (HDP), delivery of a large for gestational age baby, and congenital defects [13]. The prevalence of childhood overweight and obesity has also increased worldwide in recent decades, though with some possibility that this increase is now leveling [10].