It is lifestyle:
Still a curmudgeon in training at 48 with a wife that just turned 40... she has lost almost 40 pounds since last March with 25 of those pounds vanishing since August and has a little ways to go to get back to her pre-surgical weight. I lost the ugly weight a year ago and am working my way back up by adding lean muscle instead of body fat and that has been coming along well as I have gained 3-4 pounds in the past 6 weeks where I have been doing more weights to add some bulk.
We practice a lower carb (me) and super low carb diet (her) and avoid wheat / gluten (she has celiac disease), most grains, fruit juice, sodas, processed foods, and potatoes.
After that we eat all kinds of meat, fish, nuts, eggs, cheese, lots of vegetables, and smaller portions of fresh fruit / berries... we love Polish sausage, sauerkraut, and bacon.
The most significant weight loss for my wife happened when she eliminated oatmeal, just about all sweets, and her morning oatmeal (now she has eggs or full fat yogurt)
We don't count calories or worry about fats and even indulge in a little alcohol on a regular basis... most often whiskey with no mix.
I can maintain a healthy weight even if my activity level varies and my wife would say she has lost weight without really increasing her activity level, has not reduced her caloric intake (she probably eats a little more), and never has any food cravings.
Lower carb for me is < 150 grams a day which is half the daily allowance in the food guide with no grains / potatoes / rice
You can trim the extra weight without radical levels of activity... it goes beyond calories in and calories out and what you eat is really important. Too many carbs causes insulin spikes / drops and can lead to insulin resistance which causes weight gain.
We know quite a few people who have reversed their diabetes and gone off a lot of medications after analyzing their diets and making changes to reduce the carbs and eliminate the "healthy grains" that cause diabetics so many issues because they have such a high glycemic index.
Not drinking soda is a no brainer for anyone... that **** is poison.