This paper aims to reveal the causal relationship between energy prices and food prices and whether this relationship is similar in the food sub-groups forming the food price index used. As food prices more than doubled during the 2008 economic crisis, this relationship has received considerable attention from researchers. Many researches have been conducted to determine the causes and consequences of the 2008 food price crisis. Researches are mainly focused on crude oil and bio-energy in terms of “energy”. This research is not only differentiated by the data used but also by the methodology employed. The study attempts to add new findings to the empirical food price literature by utilizing relatively newly developed methods, namely Toda–Yamamoto causality, Fourier Toda–Yamamoto causality, and spectral BC causality tests. The spectral BC causality test clearly reveals that there is bidirectional causality between the energy price index and food price indexes (grains, other food, and oils) at different frequencies.

The study attempts to add significant outcomes to the U.S. food prices literature by performing a dynamic regression model and a frequency domain causality test to explore the causality and relationships between U.S. food prices, energy prices, economic policy uncertainty, and the value of the U.S. dollar. It is shown that dollar price negatively affects the food price index at both high and low volatility periods. Furthermore, it is presented that there is a permanent long-run causal relationship running from the dollar index to the food price index. The results indicated that there is a significant positive relationship between the energy price index and the food price index. Moreover, energy is found to be a long-run and permanent cause of the food price index. The effect of uncertainty has not been sufficiently explored in the food pricing field, the outcome of this study reveals that uncertainty increases the food price index at high volatility times. Besides, uncertainty is shown to be the long-run and permanent cause of the food price index.