BLOG: How to Lose Weight: The Calorie Question

May 11th, 2020

By Megan Zakarewicz, DO, Grand View Health Medical Weight Loss

When it comes to maintaining a healthy weight, the more you understand about the food you eat, the more power you have over your nutritional choices. Healthy choices are informed choices. Leading a healthy lifestyle doesn’t mean you never eat the chocolate cake. It means you understand the upside and the downside of your choice, and you decide when to indulge and when to refrain.

In addition to learning about nutrition, a big part of weight management is understanding your body’s nutritional requirements. Here’s what I say when someone asks me, “How many calories should I eat per day to lose weight?”

Each person has specific coloric needs. These needs are determined based on a person’s gender, weight, height, age and activity level. We calculate these needs with the following equations:

Men: calories/day = 10 x weight (kg) + 6.25 x height (cm) – 5 x age (y) + 5

Women: calories/day = 10 x weight (kg) + 6.25 x height (cm) -5 x age (y) -161

We then multiply that number by a factor based on your activity level.

This may seem complicated, but there is support to help. At Grand View Health Medical Weight Loss, we help each patient to understand how many calories you should eat per day to lose weight. You can also use an online tool to help you get started—you can find several online. I recommend you try out several tools and compare them to ensure accuracy.

Once you understand you caloric needs, the next step is to understand what foods to eat to help you meet your needs each day. We typically refer to this information as macronutrient composition. Macronutrients, or macros, are carbohydrates, fats and protein.

There are lots of opinions out there; low-fat, low-carb, high-protein. How do you know which way of eating is best for you? Many factors go into this answer, including medical conditions, body composition, weight loss goals and personal preference. For our purposes today, we’ll use the 40/30/30 principle. This means:

  • 40% of calories come from carbohydrates
  • 30% of calories come from protein
  • 30% of calories come from fat

Please keep in mind that these recommendations may not fit your specific needs. For example, people who are aiming to lower their blood sugar may choose to reduce their carbohydrate intake percentage. People pursuing a ketogenic diet would eat a much higher percentage of protein and fat. An endurance athlete may require a much higher carbohydrate intake.

Once you determine your percentage breakdown, you figure out how to apply it. I will use the example of a 2,000 calorie diet consisiting of 40% carbs, 30% protein, 30% fat.


  • 4 calories/gram
  • 40% of 2,000 calories = 800 calories of carbs/day
  • Total grams of carbs recommended per day = 800/4 = 200 grams


  • 4 calories/gram
  • 30% of 2,000 calories = 600 calories/day
  • Total grams of protein recommended/day = 600/4 = 150 grams


  • 9 calories/gram
  • 30% of 2,000 calories = 600 calories of fat/day
  • Total grams of fat recommended/day = 600/9 = 67 grams

A great way to track daily caloric intake and macros is using an online food journal or app. We have an app, available through our practice, that allows patients to track their intake. It also allows patients to ask questions and for their provider to offer feedback and advice.

This may seem overwhelming, but please know it’s not hard to find support. There are online tools to help you get started in determining your caloric needs and macronitrient ratios and also track your intake. If you would like help in getting started or more advice on how meet your weight loss goals, please schedule an appointment with me. I’d love to help you reach those goals.

About the author: Megan Zakarewicz, DO, is a primary care physician with certification in obesity medicine. She leads the Grand View Health Medical Weight Loss program. She is accepting new patients via telemedicine appointments. For more information, call Grand View Health at 215-453-4100 to schedule an appointment.