The advice to consume less fat "especially saturated fat" had a profound, adverse impact on public health. Although the percentage of fat in the American diet decreased, the percentage of carbohydrate and total calories increased, and sugar consumption skyrocketed. In The Low-Fat Lie: Rise of Obesity, Diabetes, and Inflammation, Dr. Glen Lawrence describes how the false condemnation of saturated fat arose from a misunderstanding of how our bodies regulate cholesterol. He explains how replacing saturated fat with vegetable oil stoked the fires of inflammation to cause pain and suffering, in addition to aggravating cancer, diabetes, and heart disease.

The mainstream health and nutrition authorities have long cautioned against consuming too much sugar because of the risk of tooth decay. However, they refuse to indict sugar for the gross deterioration of the nation's health and continue to blame fat, especially saturated fat. Dr. Lawrence points out that a low-fat, high-carbohydrate diet is not as effective as a low-carbohydrate diet for long-term weight loss, yet the low-fat diet mantra continues to resonate from the halls of the agencies doling out dietary advice. He also describes how sugar consumption produces classic signs of addiction in lab animals, whereas high fat consumption does not. The food and beverage industries take advantage of this phenomenon and use aggressive marketing strategies to get children hooked on sugar at an early age.

Understanding how we process what we put into our body can inform our decisions regarding dietary choices and a healthy lifestyle. Consuming more fiber in fruits and vegetables promotes a healthy microbiome, which is critical to overall health. The Low-Fat Lie also discusses:
- many ways in which gut microbiota communicate with fat tissue and other organs, including via endocannabinoid signals;
- active components of cannabis in the context of inflammation and pain; and
- how stress can influence eating patterns, while exercise can help relieve stress and suppress or control detrimental eating behaviors.

Dr. Lawrence does not prescribe any specific diet plan. Instead, he aims to enlighten the reader by illustrating the dire consequences of excessively sweetened and highly processed foods.