The main consequences in man are not retinopathy and cardiomyopathy, but slightly poorer digestion (most digestion of fats occurs in the stomach) and poorer absorption of fats, including essential fats.
Add that to a low fat diet and the person is running uphill trying to avoid depression. Consider Pritikin to be the eponym for this folly.
Does a low fat diet cause depression? Don’t be silly, but it can aggravate any depression, as can B12 deficiency, and overindulgence in the depressant substance, alcohol, which tends to produce euphoria at a low dose, but depression at much higher doses.