I ate more than a year high fat low carb diet and I felt very well. But one thing is very important: if his carb intake is low, he has to have onother source of energy and these are FATS. Otherwise he will transform the excess of protein into glucose and this is not desireble. So, his choices now are different kinds of meats: don't be afraid to cook pork, lamb or any other kind of meat. There are many kinds of high-fat cheeses, whole dairy products are great choices. Eggs are egg-xcellent. Raw nuts and low GI fruits (banans and grapes are excluded) should satisfy the need for something sweet. No pasta and no pie is not a disaster, it's in fact really healthy. Once he starts using fat as energy, he'll feel good and energetic without the bloating of the carbs ot the insulin peaks.
I wouldn't recommend using artificial sweeteners or honey (veeery high GI). Once he is used to low carb eating, he will stop craving sweets.