First of all, good for you for wanting to look and feel healthier! I have been into fitness for the past several years, so here are my 5 cents.
1) Do not go on the strict diet. It is a huge mistake that you would make because strict diet makes your body go into a “safe mode” and slows down metabolism. Once you start eating a little more than your body used to on a strict diet it will backfire and your body would turn food into fat to survive during “bad times of dieting”, instead of burning it into energy.
2) I keep to certain food plan 6 days a week and on 7th day (Sunday usually) is my cheat day, when I can eat anything I want. This meal plan boosts metabolism and does not make me feel that I am limited in food options all the time.
3) Drink plenty of water (not soda though, that’s off-limits). Helps to lose weight. At least 8 glasses per day and more if you exercise that day.
4) Cut off the salt intake. Using salt for cooking adds more salt than our body actually needs therefore it provokes water retention hence extra weight. And most of the food already has salt in it.
5) Eat 5-6 times a day in small portions (3 main meals and 2-3 snacks). The time between meals should be no longer than 4 hours. That boosts your metabolism. For example, I eat breakfast at 7-30 am, then have a snack ( banana) at 10 -30 am, then lunch at 1 pm, another snack (apple or banana or a protein bar ) at 4 pm, dinner at 7 -30 and last snack at 10 pm (apple or berries).
6) Cut off sugar 6 days a week. Although dark chocolate in the morning with coffee or tea is OK.
7) Do not eat white bread, potatoes and pasta. Substitute for the whole wheat bread and eat sweet potatoes instead, they are healthier.
8) No fast food. But as I said on Sundays I have cheat meals so I allow myself to order burger with fries or a slice or 2 of pizza.
9) Stay active. At least 3 times a week. I got to gym 5-6 times a week, that not only helps me to stay fit but also pumps up my mood.
During Holidays, in particular, I think it is OK to indulge yourself for 1 day. Next day after Christmas or Thanksgiving I go to a gym, for example, and have no regrets that I ate something prohibited the day before.
10 years ago I used to do hardcore diets before holidays and ended up being so hungry that it made me overeat at the table. That resulted in rapid weight gain during holidays. Until I learned about what influences metabolism.