I normally need to do the diet thing coming out of the holiday's (big family meals, parties, too many carbs/sweets around the house). We do a hybrid South Beach diet that works for us because we generally like the food options/choices. I don't believe in starving yourself or eating foods that you don't like because they fit in a certain diet that makes claims.
To answer your question, we'll eat red meat, chicken or fish as a protein 3-4 days a week and then meatless the other 3-4 days (legumes as the protein). My wife has found some great recipes and to be honest, I like the meatless dishes more. Simple too. Cauliflower "steaks" parmigiana, grilled cabbage steaks with pine nuts and romano cheese, deconstructed eggplant parm, spaghetti squash, with olives, feta, etc. I still drink coffee, although for the diet, we cut down on alcohol (red wine or a martini..lol). Don't drink that much water (probably 2-3 bottles a day) in addition to the coffee or a diet coke with dinner. Fill in with a Keto shake or nuts as a snack. Breakfast is a half apple with peanut butter during the week and eggs/meat on the weekend.
Cutting down the carbs dramatically is the difference maker. I have the same/more energy and don't get that carb-fog after a meal. I do like certain breads and pasta, but I could pass on anything with potatoes or rice normally. Finally, we use our fitbits as a barometer. Minimum 12k steps per day, but normally hit 20k+ 2-3 days per week (elyiptical, bike, golf-walking, etc.).
I'm not a fan of following a diet like a madman...you need to do what works for you...it's really about developing good eating habits. I love a bag of chips like anyone, but it's all about moderation (which is not easy).