The Paleolithic diet, a diet devoid of food-processing procedure, seems to produce a greater decrease in weight compared to healthy reference diets but its limited food choices make it difficult to implement in our modern times where refined food is dominant.
To evaluate the effects of a 2-year diet that excludes only six refined foodstuffs implicated in obesity. Professional contact was kept minimal to approximate the approach used by most dieters.
Single-arm, open-label, exploratory study.
One academic medical center, outpatient setting.
One hundred and five subjects with a mean age of 50 (SD, 14 years) and mean body mass index of 30.5 kg/m2 (SD, 4 kg/m2). Thirty-nine percent had type 2 diabetes.
An ad libitum diet that excludes six refined foodstuffs (margarine, vegetable oils, butter, cream, processed meat, and sugary drinks) called the "1,2,3 diet".
Weight at 2 years was the primary outcome. Secondary outcomes included number of patients who lost more than 5% of initial body weight, glycated hemoglobin (HbA1c) level, and changes in dietary behavior.
Average weight loss was 4.8 kg (p<0.001), representing 5.6% of their initial body weight. Among completers (51%), the average weight loss was 5.5 kg (p<0.001), and 56% had a reduction of at least 5% of their initial body weight. Among diabetics, weight loss was similar to nondiabetics, and mean HbA1c level decreased by 1% (p=0.001) without modification in glucose-lowering medications. A higher intake of bread, dairy products, chocolate, and fresh fruits was the typical trend in dietary changes reported by completers.
In this exploratory study, there was a significant long-term weight loss with the "1,2,3 diet" despite minimal professional contact. Given the lack of a control group and high attrition rate, further evaluation of this diet is warranted.