Recent nutritional research examines the earliest human diet, the Paleolithic diet or paleodiet, in search of answers to recent health crises such as obesity and diabetes.
The paleodiet was full of variety and was sourced mainly by hunting and gathering. Early humans consumed berries, fruits, plants, as well as small and large game. However, due to climate change, migration, and population growth, over time, starches such as tubers and roots became a larger part of the human diet. During the Neolithic period technological and societal advancements paved the way for primitive crop and livestock farming. This shifted the food sources away from the natural environment toward standardization and domestication and led to increased consumption of milk and single grain cereals. 
The Shift to Convenience Foods
Twentieth century human diets shifted again and continued to build on economies of scale resulting from agricultural and animal domestication and the rise of food manufacturing. More refined and processed foods made their way into the human diet. Late 20th century diets evolved to more highly-processed, convenience foods high in sugar and fat. Sugar consumption increased by 39% from the 1950’s to the year 2000. This means the average American eats more than 152 pounds of sugar each year. In addition, refined grain consumption increased more than 20%, pushing grain consumption over the USDA recommended daily allowance. 
Health Impacts of Convenience Foods
Diets high in refined grains, sugar and fat significantly contribute to obesity and raise levels of blood fats called triglycerides. Triglycerides are an important marker to assess risk of cardiovascular disease, stroke and diabetes. Shifting away from fatty, sugary, highly processed convenience foods back to a diet filled with whole, natural fruits, vegetables and lean proteins can lower triglyceride levels.