Calories get a bad rap. Essentially, they’re a way of measuring your body’s energy source, a simple unit of fuel that drives us and thrives, derived from the foods and beverages we consume. Each of us requires different amounts of energy depending on our age, daily activity level, body composition, innate metabolism, and even our stress level (we burn more when we’re under the gun).
When it comes to weight loss, calories are just one of the most important things to focus on – getting the most nutrients for your calories is important to fuel a healthy body. Still, in the laws of thermodynamics, no matter what type of diet you’re following (plant-based, keto, vegan, or paleo), if you’re consuming more calories than you’re burning or needing in the next short period of time, that extra fuel will be than fat stored. The opposite is also true: Eat less calories than you need and you will go into what is called a calorie deficit and your body will burn energy, first the stored energy in your muscles and liver, and then it will mobilize the stored fat for fuel. Here’s how to implement a calorie deficit and do it the healthy way to lose weight and keep it off.
What is a calorie deficit? Is it a safe way to lose weight healthily?
A calorie deficit means you are consuming fewer calories than your body needs on a daily basis. This is called your basal metabolic rate (BMR), which is basically how many calories your body needs to keep the body functioning at rest.
That National Health Service states that a safe weight loss rate is between 1 and 2 pounds per week. Achieving this requires a calorie deficit of 500 to 1,000 calories per day since there are 3,500 calories in a pound of fat.
To start losing weight, first dip into the “shallow end” of the pool, which means you only strive to create a small calorie deficit (no more than 500 calories) so as not to overwhelm your body through drastic calorie restriction or shocking an extreme deficit, which can backfire as your body will think it is starving to the point where it will try to hold onto whatever you give it.
Eliminating 500 calories a day is doable through diet alone, but it’s even easier and healthier when combined with exercise. When we run or walk, ride a bike or swim, our body uses extra energy to fuel our muscles. That CDC recommends getting at least 150 minutes of moderate-intensity activity each week. Broken down, that means about 30 minutes a day, five times a week. More intensity burns more calories and so does longer training.
How to calculate your body’s calorie needs
You can calculate your calorie requirement (BMR). from a formula for men and women. They are as follows:
- Male: 66 + (6.3 x body weight in pounds) + (12.9 x height in inches) – (6.8 x age in years)
- Female: 655 + (4.3 x weight in pounds) + (4.7 x height in inches) – (4.7 x age in years)
After calculating your BMR, you also need to factor in your activity level. Take the number you calculated from the formula above and multiply it by the following numbers depending on how active you are:
- Sedentary lifestyle (little to no exercise) = 1.2
- Minimum activity (1 to 3 days of training per week) = 1.375
- Moderate activity (3 to 5 days of moderate exercise per week) = 1.55
- Very active (6 to 7 days of intense exercise per week) = 1,725
- Extra active (athletes who train multiple times a day) = 1.9
This is a good starting point for determining how many calories you need each day. Working with a registered dietitian is also helpful for a more accurate estimate and assistance with setting the right calorie deficit for weight loss.
The quality of your calories is important
Even if you want to cut your daily calories by more than 500 a day, remember that not all calories are created equal. A 500-calorie salad loaded with greens, veggies, seeds, and grains will provide you with more nutrients than snacking on a big bag of chips or pretzels, which are high in salt, refined flour, oils, and added preservatives. Eating more whole foods like fruits and vegetables can help keep stress at bay, improve your sleep, and keep your gut microbiome healthy — other important aspects of weight loss that go beyond simply creating a calorie deficit.
That 2020-2025 Dietary Guidelines for Americans suggest following a healthy eating pattern consisting of a mix of whole foods. Plant-based choices can replace traditional dairy:
- Vegetables, including starchy, dark green, red, and cruciferous vegetables
- Fruits, especially whole fruits, berries, apples and citrus fruits
- Grains, with most coming from whole grains like oats
- Protein, including lean meats, legumes, nuts, and soy products
- Healthy oils like olive oil, avocado, nuts and seeds
- Plant-based milks and yoghurts made from cashews, almonds, oats and macademia
Research has shown that a plant-based diet is helpful for improving body weight and fat mass. According to a 2018 study published in Nutrition & Diabetes, each reduction in animal protein and increase in plant protein contributed to reducing fat mass by 1.45 and 0.88 kilograms, respectively. It is believed that the amino acid composition of plant proteins is superior to that of animal proteins and can not only help reduce fat mass and body weight, but also protect against metabolic diseases.
An extreme calorie deficit can negatively affect metabolism
Just as eating too many calories can lead to weight gain, not consuming enough calories to fuel your body can also negatively impact your metabolism and have long-term effects on your ability to achieve healthy weight loss — not to mention yours general health. It can be tempting to try to rush the process, but gradual and steady weight loss is the best option for keeping it off long-term.
according to a Article 2013, following a low-calorie diet can decrease the number of calories your body burns by up to 23 percent. This means your body learns to survive on smaller amounts of calories by slowing down your metabolism, which can remain low even after you stop restricting your calories.
When calories are cut too drastically, you also increase your risk of health problems and a weakened immune system. This contains:
- nutrient deficiency
- Increased risk of gallstones
- bone loss
- Reduced fertility
Some signs that you are not consuming enough calories are:
- Get sick often
- Stopped weight loss
- Depressed mood
- tiredness and drowsiness
A good rule of thumb is never to go below the calories indicated by your BMR calculation.
bottom line: Being in a calorie deficit is a big part of weight loss, but it’s important to make sure you’re not overly restricting calories and choosing nutrient-dense options.
There is safe ways to lose weight that don’t involve being hungry or going into a calorie deficit. Read more about how you can improve your health and well-being Diet & Weight Loss Section.