Venice can get pretty cold and they also have those famous Acqua Alta floods in winter, so read up on that before you go. But Rome and Munich should be easy to visit in December. One suggestion I will make is to consider visiting Rome for 3 or 4 nights and then base yourself down on Sorrento for the remaining 2 or 3 nights. Rome is one of those cities that is crowded and chaotic even in winter, to the point that just crossing the street can be frustrating, so many people get tired of that after they’ve seen the main sights. And Sorrento, on the other hand, is a lovely small city that is close to Amalfi, Pompeii, Naples, and the Isle of Capri, so it’s an ideal base to visit all of those. Sorrento is also cheaper than Rome, and a surprising number of locals speak English there, so it’s easy and pleasant. That time of year I’m not even sure if the tourist buses are running to Amalfi, although the local ones will be.
If you crave warmth but think the beach bores you, head to the Southwestern United States. New Age meets Old West in Santa Fe, Phoenix is still toasty and its cultural season is in full swing, and Denver makes for a great trip. And if you've never seen the Grand Canyon, winter is a good time to visit since the crowds have thinned out (but do dress warmly).
If intermittent fasting is part of your low-carb routine, use it strategically to skip meals and make travel simpler. Perhaps you rush to your early morning flight and wait to eat until lunch. Or, eat a hearty low-carb breakfast before leaving home and don’t eat again until dinner at your destination. One nice thing about fasting is that you can do it anywhere.
Located off the coast of East Africa, the Seychelles—an archipelago consisting of 115 islands—is about as close to paradise as you can get. Crystal clear water, lush jungles, and powder-fine sand make it the ultimate early winter escape, particularly for romantic getaways. Book one of the 30 breathtaking pool villas at Six Senses Zil Pasyon, which is among the region's top luxury resorts. The hotel is situated on a private island that offers prime territory for snorkeling, sailing, kayaking, and hiking—plus, the spa has scenic pavilion-style treatment rooms that are worth the trip alone. Health conscious guests will be particularly impressed by the property's new "Eat with Six Senses" program, which is intended to make travelers leave vacation without the guilt that comes with overindulging. There are four tailor-made treatment plans that focus on sleep, detoxing, fitness, and more, depending on the issues you prefer to address.