The paleo diet is promoted as a way of improving health. There is some evidence that following this diet may lead to improvements in terms of body composition and metabolic effects compared with the typical Western diet or compared with diets recommended by national nutritional guidelines. There is no good evidence that the diet helps with weight loss, other than through the normal mechanisms of calorie restriction. Following the paleo diet can lead to nutritional deficiencies such as an inadequate calcium intake, and side effects can include weakness, diarrhea, and headaches.
I often get caught up in focusing on numbers and scales, so I decided not to officially weigh myself before or after Whole30. But I can attest that everything about my body just felt better. I know saying something like "I lost eleven pounds" would sound much more convincing, but I could see that my stomach was slimmer, as was my face (which is awkwardly the first place I gain weight).
The WHO trial (so named because the international team of principal investigators contained World Health Organization members) tested the potential of clofibrate, a “pre-statin” cholesterol-lowering agent, to reduce heart attack morbidity and mortality. The investigators ultimately concluded that clofibrate "cannot be recommended as a lipid-lowering drug for community-wide primary prevention of ischaemic heart disease.” Nevertheless, clofibrate remained in use until 2002, when it was pulled for increasing cancer rates. In their review of studies such as the WHO trial, Uffe Ravnskov and David Diamond observe, “Despite the largely disappointing findings from 50 years of cholesterol lower[ing] trials, the indictment and conviction of cholesterol as the causal agent in CVD [cardiovascular disease] has stood the test of time. … [Yet] the grand effort to reduce cholesterol as a strategy to improve health has failed.”