What Is a Calorie Deficit and Is It Safe?

What Is a Calorie Deficit, and Is It Safe?

It has been long held to be that having a caloriedeficit is a typical strategy to employ in order to shed weight. (You've likely heard or seen the phrase "calories in < calories out" at some point, right?)

But what is an caloriedeficit, anyway and is cutting down in calories the best way to lose weight? Here's what nutrition experts and research from recent years say regarding calorie deficits and the best way to calculate a calorie deficit and whether they're appropriate.

CREDIT: ADOBE STOCK

What Is a Calorie?

In terms of the human body, a calorieis an amount that indicates the quantity of food products that have an energy-producing value. It is basically that the food and beverages you consume provide you with the energy which is measured in terms of calories, which is required to be able to live.

But, your body requires more than just food for survival -- you also require nutrientssuch as vitamins and minerals to keep your body functioning properly. (For instance, the mineral calcium found in milk strengthens bones, while the mineral iron found in beans is essential to support the function of red blood cells.)

How Many Calories Do You Need Per Day?

Three factors determine the total calories you need: your basal metabolic rate, physical activity, and the thermic effect of food.

Basal metabolic rate:Your basal metabolism is the amount of energy required for your body to simply remain alive, for instance, for your heart to pump. The basis metabolic rate (BMR) is influenced by many factors , including gender, age and height as well as growth (i.e. in the case of children). Basal metabolism accounts for about 50-70 percent of your calorie requirements.

Physical exercise:Physical physical activity is responsible for 25-40 percent of your calorie needs. It obviously includes workouts, but it is also non-exercise activity thermogenesis, commonly referred to as NEAT. the energy that is burned as you perform tasks that are not breathing, digesting and eating or doing any exercise, i.e cooking, cleaning fidgeting, typing and so on.

Thermic effects of foodThe thermic effect of food refers to the energy required to help digest food you eat. It's a factor that accounts for anywhere from 5 to 10 percent of your calorie needs.

Dietitians use various formulas to determine a person's calorie needs. One of the most popular methods is called the Harris-Benedict Equation In the beginning, you determine your BMR with your weight, height, and age. Next, it is then your BMR is multiplied by an exercise factor (ex how much you move on a daily basis) to determine roughly how much calories you'll require each day. For example, someone who doesn't exercise often or at all multiplies their BMR by 1.2 or less, while an exerciser who exercises moderately up to five times per week will increase the BMR by 1.55. Instead of doing all the calculations on your own, you can utilize to use the USDA's calculator to determine your calorie requirements. USDA CALORIE NEEDS CALCULATOR

Adult women's needs for calories can range from 1,600- 2,400 daily, according to the Academy of Nutrition and Dietetics. If your lifestyle is active, you'll fall on the lower side of the range. If you're more active, you'd be on the upper side. (Note when you age, your calorie requirements decrease when you're pregnant or breastfeeding the need for calories may rise.)

What Is a Calorie Deficit?

Simply put in simple terms, the definition of a calorie deficit is the result of eating fewer calories than your body is using or burning.

It is generally recommended that, in order to lose weight, it is important to create an calorie deficit. For example for a person who needs 3000 calories a day however, reducing your calorie intake to 2,500 calories will result in the calorie shortage of around 500 calories per day. In 1558, researcher Max Wishnofsky, M.D. estimated that one kilogram of fat contains approximately 3,500 calories of energy, from an article published in "Today's Dietitian. Since then, it's become common information that, in terms of weight loss, 1 pound is equivalent to 3,500 calories. To put that into perspective, the concept is that a daily 500-calorie deficit will ultimately lead to about 1 pound weight loss each week. (See: How to Cut Calories to Lose Weight Safely)

If you're eating higher amounts of calories than your body requires, that's called a calorie surplus. If you're in the calorie surplus for a prolonged period duration, it can result in weight rise. (Of course, significant weight increase isn't always the result of overeating -- it can be due to metabolic problems or other health issues , such as hypothyroidism. It's the reason it's so important to schedule annual medical check-ups and see a doctor if you start losing weight suddenly.)

Using a Calorie Deficit for Weight Loss

The National Institute of Health (NIH) broadly recommends eating a diet that is low in calories (aka creating a caloric deficit) for those who are overweight or obese and seeking to lose weight. The Academy of Nutrition and Dietetics also specifies in a 2016 report that a daily 500- to 750- calorie deficit is indeed recommended to lose weight.

The research that has been frequently cited supports this idea: A 2007 study on calorie deficits showed that cutting back on about 500 calories daily can help to lose weight. However, the amount of weight lost is contingent on the body weight, as per the research. For instance, someone who is born with a larger percentage of body fat has to have an increased calorie deficit to lose weight. This is why males can be more weight-loss than women within the same calorie deficit, as women typically have more body fat than men of similar body weight.

However the report from the year 2014 that was published in International Journal of Obesitypoints out that the guideline of a 3500-calorie deficit per week (or 500-calorie deficit per day) as a general rule that can be over-simplified. Researchers conducting the study wanted to find out if the 3500-calorie rule could predict loss of weight of subjects, but the results showed that most of the participants lost significantly more weight than the amount suggested in the 3,500-calorie rule. In reality, there are many more factors affecting the results of weight loss than simply cutting calories. Many metabolic factors including internal satiety cues (meaning that you're feeling full or content), can also have an impact. There's a great deal of work being done to determine other things that might be involved.

How to Safely Lose Weight Using a Calorie Deficit

While research has shown that the 500-calorie deficit rule may not be foolproof, it's the recommended guideline for losing weight by public health agencies such as the NIH, Academy of Nutrition and Dietetics and the Mayo Clinic. If you want to lose weight through being in a calorie deficit, you'll need to maintain it over more time, says Joan Salge Blake, Ed.D., R.D.N., nutrition instructor of Boston University and host of the popular podcast on health and nutrition called Spot On!. You can set up and keep a calorie loss by

1. Consuming fewer calories.
2. Increasing your daily physical activity while reducing your calorie consumption.
3. A combination of both.

It's true that cutting back on calories in conjunction with exercising more (and so producing more calories) is the most effective method for folks to lose weight according to Salge Blake. (Think about it this way: If you cut out 250 calories from your daily routine and do the treadmill or take a walk which burns 250 calories it could be more easy to attain the 500-calorie target than the reduction in your food intake of 500 calories only.)

But, you don't necessarily want to do anything extreme by avoiding all food and over-exercising because it isn't lasting or healthful in the long run. "Just because a little calorie deficit is good for weight loss does not mean that eating as little as possible to lose weight is a good idea," says sports dietitian Amy Goodson, M.S., R.D. Do not eat less than 1,000 calories per day, according to NIH. If you're taking in too few calories, it may hinder weight loss and block your body from getting the calories it needs for a healthy lifestyle. If you're eating fewer calories, even for one day, you can feel unsatisfied, hungry as well as fatigued. You may also experience diarrhea and/or constipation. This doesn't inform good eating habits that can be sustained. If you reduce calories over a long period of time (think months) that could lead to malnutrition, nutritional deficiencies and cause you to be feeling hungry. Because of this, the body will keep on to the fat in order to back-up energy for your body and will ultimately hinder on weight loss and would be detrimental to your goals.

A safe rate of reduction in weight ranges from between 1 and 2-pounds per week as per the NIH. Anything more than that may possibly be risky and cause serious health implications. Quick weight loss increases demands on the body . It can also make it more likely to develop developing gall stones or malnutrition, electrolyte imbalances, and damage to the liver. If the rate of weight loss exceeds 1 to 2 pounds per week (i.e. during bariatric surgeries) the procedure must be monitored by a team of medical experts.

Also, it's worth noting there is a risk that if you have an underlying medical condition that may be causing weight increasing (such as type 2 diabetes or hypothyroidism) try using the concept of a calorie deficit to reduce weight may not work. That's why it is important to see your doctor if you recently gained a significant amount of weight, or if you've been trying to shed weight but haven't succeeded.

Short- vs. Long-Term Weight Loss Goals

"Depending on the person and their specific weight-loss goal, a calorie deficit may need to be done for a shorter or longer amount of time," says Goodson. "While it's not always a perfect equation, typically the length of calorie deficit depends on the amount of weight that needs to be lost." But after six months of using to maintain a calorie deficit to lose weight it's essential to shift to a weight-maintenance plan - regardless of whether or not you've met your goals, according to the National Institute of Health. If you've lost weight, losing it will be challenging. Breaks for a few months or weeks to be sure you don't return to it can help maintain your weight loss long-term. According to the Transtheoretical Model (or Stages of Change) which is used to explain behaviour changes, the fifth phase is the maintenance phase where the behavior is sustained (for longer than six months) and is designed to be maintained throughout the future. When you enter this mode of maintenance after a few months of being in a calorie deficit isn't all about how much food you're consuming however it is about giving yourself time to adjust your habits and, based on this model, 6 months appears to be the ideal number. Then, once you've kept off the weight for some months, you're able to revise your calorie requirements and set new deficits to sustain your losing weight.

On that note, when you hit a plateau in your weight loss which can happen and is a common aspect of the weight-loss process -- it's essential to reconsider your calorie requirements since a second deficit (though maybe not as large) may be needed. For instance, if, for example, you lost 10 pounds by eating 500 calories less per day for a period of about 2 months in a row, your calorie requirements will be less due to the fact that you're 10lbs lighter. Therefore, you might have to reconsider your calorie requirements based on your BMR and your level of exercise; you may end up having 750 calories less the day you began.

Similar to the way, when your weight loss target is met, you'll need to adjust your calorie intake accordingly. Engaging in physical activity on a regular basis can also assist in maintaining your weight loss by increasing your overall calorie burn (as well as providing your body with numerous other significant health benefits).

The most important thing is to sustain weight loss over a prolonged period of time , and not be able to see your weight climb back up. That's the reason the NIH advises no more than 500 to 1000 calorie deficit per day. "The trick is to create small calorie deficits so that the weight you lose doesn't come back," says Elizabeth Ward, M.S., R.D., author of Better is the New Perfect. If you attempt to keep a large calorie gap, then you'll likely be extremely hungry and will not stick to your meal plan for as long a period of time, effectively stopping your efforts to lose weight. Long-term weight loss that is sustained over time is much more challenging than losing the weight, according to research from a 2018 study. In the meta-analysis of 29 lengthy weight loss studies, more than half the weight loss was regained in less than two years. In the following five years, more than 80 percent of lost weight was regained.

Calorie Deficit and Exercise

People who are physically active might wonder if they can shed weight using the use of a calorie deficit. "The key is making sure that you're fueling your body appropriately for the amount of activity being done," explains Goodson. "Consuming too few calories can have a negative impact on performance and energy levels." For example, if cutting calories or doing a lot of exercise, you might be at risk for Female athlete triad syndrome. This manifests as irregular menstrual cycles and loss of energy.

"Tracking calories may be an important piece of the equation to make sure active people consume enough calories for energy but are creating a deficit to help them meet their weight loss goal," says Goodson.

As a general rule is to reduce consumption of calories and increase the amount of exercise they do to make a deficit in calories. But if you're an athlete (think that you're running for a marathon, or other vigorous event) or have significant amount of weight to lose you might want to speak with an accredited dietitian who has a particular interest in sports.

Behavior Change

Reducing calories and working out more is only half of the combat. The NIH also suggests that behavior therapy be used when combined with weight loss and more physical exercise. Based on the Transtheoretical Model (or Stages of Change) Once you've sustained a behavior for more than 6 months and then it becomes an habit that people continue to engage in. Creating healthy habits that last for the rest of their lives is the final goal of keeping off the weight.

Salge Blake recommends meeting an licensed dietitian nutritionist (RDN) who specializes in this area to help you on losing weight. This service could get covered under your health insurance. Find an RDN near you through the Academy of Nutrition and Dietetics website and then clicking on "Find an Expert."

Why a Calorie Deficit Doesn't Always Work

It is true that a calorie deficit could result in weight loss. However "many folks over-estimate how many calories they are burning through physical activity and underestimate how many calories they are consuming," says Salge Blake. Research has also shown that cardio machines as well as other calculators for burning calories may underestimate. This can make trying to shed weight solely through increased physical activity -- or by the calculation of your calorie deficit while including calories burned in exercise more challenging.

If you're trying keep track of to track your calorie surplus, Salge Blake recommends using one of the many weight loss apps that can help you keep track of the food you're eating. Keep in mind "you need to understand portion sizes in order to put in the accurate amounts of the foods you're consuming daily," explains Salge Blake. "If your portions are incorrect -- especially, underestimated -- so will be the output [your total calorie count]."

In order to meet your calorie needs and take in the necessary nutrients to stay healthy it's essential to prioritize eating foods that are rich in nutrients and avoid food items high in saturated fat along with added sugars. The 2020-2025 guidelines for dietary recommendations for Americans provide the 85/15 rule for guidance, where 85 percent of the calories consumed must come coming from sources rich in nutrients and 15% could be derived from sources that aren't calorie-dense, such as those higher in saturated fats and sugars added (think chocolate, cookies or butter, etc.). (Related: These 5 Simple Nutrition Guidelines Are Undisputed By Experts and Research)

Furthermore, if have a history of eating disorders (such as anorexia , bulimia, or orthorexia) and you are a bulimia sufferer, you might not be a good option for calorie counting as the tedious character of calorie counting could trigger an repeat relapse. In addition, those with eating disorders spend many months or even years learning new eating patterns and focus on removing eating disorders, which includes calorie counting. According to a paper from 2010 released in the Journal of Neuroscience, calorie restriction can lead to anxiety and eating disorders even in people who do not have a history of eating disorder. (Related: Counting Calories Helped Me Lose Weight--But Then I Developed an Eating Disorder)

The Bottom Line

Utilizing using a calorie deficit to shed weight is definitely a strategy that works, but not by itself. Increasing exercise, understanding how to estimate what you eat (like portions) and changing your behavior towards healthy, sustainable practices are also part of the formula. While many have accomplished this by themselves, having the guidance of an RDN can be a great help in providing support and positive motivation towards healthy weight reduction goals.