What fad diet of the early 2000s emphasized high protein and very low carbohydrate intake?

The diet that captured significant public attention in the early 2000s, championing a regimen of high protein and drastically reduced carbohydrate intake, was the Atkins diet. Devised by cardiologist Robert C. Atkins in the 1970s, its popularity surged in the new millennium, becoming a household name for weight loss. During its peak around 2002 to 2004, an estimated one in eleven adults in North America reportedly followed a low-carb eating plan such as Atkins, demonstrating its widespread influence on dietary trends.

The core principle of this dietary approach revolved around severely restricting carbohydrates, particularly in its initial "Induction" phase, where daily intake could be as low as 20 grams, primarily from specific vegetables. By limiting carbohydrates, the diet aimed to shift the body's metabolism into a state called ketosis, where it burns stored fat for energy instead of glucose. This meant followers were encouraged to consume protein-rich foods like meat, eggs, and cheese, along with healthy fats, while staples like bread, pasta, and sugary items were largely forbidden. This shift in eating habits even impacted the food industry, with declines reported in the sales of carbohydrate-heavy products.

Despite its considerable following and claims of rapid weight loss, the Atkins diet also generated considerable debate within the medical community. Critics often pointed to its high saturated fat content and potential to be nutritionally unbalanced, raising concerns about long-term health implications such as an increased risk of heart disease. However, proponents and some studies suggested short-term benefits including weight loss and improvements in certain metabolic markers. Over time, the diet has seen revisions, with newer iterations encouraging a broader range of vegetables and even addressing the needs of vegetarians.