Replace some or all of the all-purpose flour with whole wheat flour to increase fiber content and make the cake more filling.
Incorporate Greek yogurt instead of sour cream or butter to reduce fat content while adding protein and moisture to the cake.
Use natural sweeteners like honey, maple syrup, or coconut sugar instead of refined sugars to lower the glycemic index of the cake.
Enhance flavor with freshly grated lemon zest and juice instead of artificial flavorings or concentrates.
Opt for a light glaze made with powdered sugar and lemon juice instead of a heavy buttercream frosting to reduce overall sugar and fat content.