A January 2020 study by Department of Surgery, University of Chicago Medicine and colleagues from the Department of Urology, Northwestern University Feinberg School of Medicine, and the Department of Surgery, NorthShore University Health System found that, "…men who adhered to a fat restrictive diet had lower serum testosterone than men on a nonrestrictive diet," but that, “… the clinical significance of small differences in serum T across diets is unclear."
In passing … some good foods for testosterone are oysters, egg yolk, shellfish, tuna, low-fat milk, fortified cereals, beans and beef.