“When it comes to mealtime, the better you plan, the better you do,” says Brian Wansink, Ph.D., author of Slim by Design: Mindless Eating Solutions for Everyday Life. Rather than leaving your nutrition up to chance, practice these weekly rituals to lose your gut and add calorie-torching muscle.

These nine essential tips will make it easy to maintain a healthy diet even on the most stressful day of the week:

1. Plan Your Weekly Meals Ahead of Time

If you fail to plan, plan to fail. Preparation is the key to success when trying to achieve your fitness goals. Plan what you will eat as well as when you will eat it to see the best results with your weight loss efforts. "Plan what you'll eat as well as what time you'll eat it," says Trisha B. Stavinoha, RD, CSCS, a registered dietician and strength coach in the U.S. Army.

The fewer food choices you have on any given day, the better you will eat. "Research shows that people who eat the same breakfast every day, oatmeal and two eggs for example, tend to be healthy for life. Namely because they have removed the possibility of splurging on unhealthy food," says Wansink. Packing pre-planned meals for work is key in cutting out the opportunity to choose something unhealthy.

2. Make a Grocery List and Stick to It

Let's say you plan to eat five daily meals Monday through Saturday. If you’re running to the store once per week, you’ll need to pick up around 30 servings of lean protein, like eggs, chicken and tilapia. You'll also need about twice that amount of lower-starch carbs, like green beans, broccoli and spinach, plus some high-star carbs, like brown rice, whole wheat pasta, and sweet potatoes.

"You shop smarter by planning ahead and limiting the variety of items that come in a box," says Stavinoha. You can shop even smarter by sticking to the fresh sections of the grocery stores where products are fresh and free of many additives that you will find in the other sections. The key is to invest in fresh, quality ingredients that you will use to prepare your food for the week.

3. Prepare Food Once or Twice a Week

If you plan on cooking only once a week, you'll cook all of your weekly meals over a few hours on Sunday afternoon. If you prefer to break it up into two sessions, try dividing the work between Sundays and Wednesdays.

Cooking all of your meals in one, possibly two sessions will save you a lot of time each week. You will use all of the same utensils to chop and prepare your ingredients which will results in doing dishes only once per week. You cant beat that!

Knowing how to prep is the first step to weight loss success. Generally speaking, to gain muscle without adding body fat or drop fat without losing too much muscle, you must determine your daily calorie needs. Then, cook your food according to what you’ll need each day and how much you plan to exercise.

4. Have Quality Containers

If you want a kitchen that encourages fat loss and muscle gain, you need to pre-portion and package all of your meals for the week. That way, you'll always have a healthy option and no excuse for turning to larger portion sizes or something fattening. "An empty kitchen is problematic because, when you get hungry, you don't have any healthy options," says Wansink.

Stock up on quality containers! Another helpful tip will be to label all of your containers. You can use your own labeling system such as labeling all of your breakfasts, lunches, and dinners differently. The key here is to stay organized when preparing your meals, which will make it easier to stay focused during the busy week ahead!

5. Organize Your Fridge

Move all of your healthy and prepared food to the front of your fridge! "Seeing healthy food primes you to make good choices, in the same way seeing unhealthy food encourages you to make bad choices," says Dr. Wansink.

Ethylene gas is a naturally occurring plant hormone that speeds up the ripening process. To increase the shelf life of your produce and save money on grocery bills, separate ethylene-producers (like avocadoes, ripe bananas and tomatoes) from the veggies that are spoiled by the gas (broccoli, spinach and sweet potatoes).