What Is a Calorie Deficit and Is It Safe?

What Is a Calorie Deficit, and Is It Safe?

It has been long held the notion that being in caloriedeficit is an effective strategy in order to shed weight. (You've likely heard or witnessed the expression "calories in < calories out" at the time, right?)

What exactly is a caloriedeficit and what exactly is it and is cutting down on calories the most effective method of losing weight? Here's what nutritionists and recent research say about calorie deficits, how to calculate a calorie deficit and whether they're a good idea.

CREDIT: ADOBE STOCK

What Is a Calorie?

With regard to the human body it is calorieis the measurement which indicates the amount of food that has a particular energy-producing value. This basically means that the food and beverages you consume provide you with the energy, calculated in terms of calories to stay alive.

However, your body requires more than just food to keep you alive. you also need nutrients -- including vitamins and minerals for you to ensure that your body is functioning well. (For example the mineral calcium in milk strengthens bones while the iron mineral found in beans is necessary for the functioning of red blood cells.)

How Many Calories Do You Need Per Day?

There are three elements that determine the total calories you require: your basal metabolic rate, your physical exertion and the thermal effect of food.

Basal metabolic rate:Your basal metabolism is the amount of energy you require for your body's needs to stay alive, such as for your heart's pumping. The rate at which a person's BMR (BMR) depends on numerous factors , including gender, age, height, and growth (i.e. in the case of children). Basal metabolism makes up about 50-70 percent of your calorie needs.

Physical exercise:Physical activity accounts for between 25 and 40 per cent of calorie requirements. Thisobviously is not just about exercise, but also includes non-exercise thermogenesis or NEAT, the energy you expend in doing things that are not breathing, digesting food, eating, or exercising, i.e cooking, cleaning, fidgeting, typing, etc.

Thermic impact of food:The Thermic impact of foods is the energy required for digestion and absorption of the food you consume. It's responsible for 5 to 10 percent of your total calorie requirements.

Dietitians use various formulas to determine a person's calorie needs. The most popular formulations that is used to determine this is the Harris Benedict Equation The formula is based on the following steps: first, you determine your BMR by calculating your weight, height and age, and then you calculate your BMR is multiplied with an activity factor (ex what you move on a daily basis) to figure out how many calories you require per day. For instance, a person who does not exercise regularly or rarely multiplies their BMR by 1.2 for example, while an exerciser who exercises moderately up to five times per week will multiply their BMR in 1.55. Instead of doing all the calculations on your own, make use of this USDA's calculator to figure out your calorie needs. USDA CALORIE NEEDS CALCULATOR

Women's calories for adults range from 1,600 to 2,400 daily, according the Academy of Nutrition and Dietetics. If you're more sedentary, you'd be on the lower side of the spectrum, while if you're more active, you'll be at the upper end. (Note that as you get older, your calorie needs decrease, and if you're pregnant or breastfeeding it could be that your needs increase.)

What Is a Calorie Deficit?

Simply stated the way it works, it is a calorie deficit is the result of eating fewer calories than your body is burning or using.

It's commonly advised that, in order to lose weight, you must create the calorie deficit. For example for a person who needs to consume 3,000 calories daily then reducing their calorie intake , to around 2,500 calories results in a calorie reduction of approximately 500 calories daily. In 1558, researcher Max Wishnofsky, M.D. discovered that 1 pound of fat stores approximately 3,500 calories of energy in a report published in The Today's Dietitian. Since then, it's been common information that, for weight loss, one pound is equivalent to 3,500 calories. With that in mind, the concept is that a daily deficit of 500 calories will ultimately lead to about 1 pound of weight loss every week. (See: How to Cut Calories to Lose Weight Safely)

If you're using excess calories than your body requires, that's called an calorie surplus. If you're in an calorie surplus for a prolonged period of time, it might frequently lead to weight rise. (Of course, significant weight growth isn't always caused by excess eating, it can also result from metabolic issues or other health issues , such as hypothyroidism. This is why it's imperative to attend annual medical checks and consult an expert if you notice that you're losing weight suddenly.)

Using a Calorie Deficit for Weight Loss

The National Institute of Health (NIH) broadly recommends adopting a low-calorie diet (aka creating a caloric deficit) for people who are overweight or obese and are looking to lose weight. The Academy of Nutrition and Dietetics further states in its 2016 report that the daily 500- 775or more calorie deficit is recommended for weight loss.

Research that is often cited supports this method: A 2007 study on calorie deficits proved the reduction of about 500 calories a day can assist in losing weight. However the amount lost will depend on the individual's body weight, in accordance with the study. For instance, someone who has a greater percentage of body fat has to have an increased calorie deficit over time to shed weight. This is the reason men shed more pounds than females within an exact calorie deficit since women typically are more fat-laden than men of similar body weight.

However the 2014 study released in the International Journal of Obesitypoints out that the guideline of a 3500-calorie deficit per week (or 500 calories deficit per day) as an average rule of thumb that could be simplified. Researchers involved in the study wanted to determine if the 3,500-calorie rule could accurately predict weight loss of the subjects however, the results revealed that the majority of people lost significantly lower weight than the amount suggested in the 3,500-calorie rule. There are many other factors that affect the weight loss results, beyond cutting down on calories. Many metabolic factors like internal signals of satiety (meaning that you're full or satisfied) are also able to influence your weight loss. There's plenty of research being conducted to study other factors that could be a factor.

How to Safely Lose Weight Using a Calorie Deficit

While studies show that an ad hoc 500-calorie threshold may have some flaws, the rule is still the most recommended way to lose weight for public health organizations such as the National Institute of Health, Academy of Nutrition and Dietetics, and the Mayo Clinic. If you want to lose weight by establishing an calorie deficit, it is necessary to maintain it over an extended period of time, suggests Joan Salge Blake, Ed.D., R.D.N., nutrition instructor in the nutrition department at Boston University and host of the nutrition and wellness podcast On! On!. It is possible to create and maintain a calorie deficit by:

1. Consuming fewer calories.
2. Intensifying your physical activity without increasing your calorie consumption.
3. A mix of both.

It's true that cutting back on calories in combination with getting more active (and therefore losing more fat) is typically the most efficient way to shed weight According to Salge Blake. (Think of this: If you take off 250 calories from your day and go on an exercise or walk which burns 250 calories it could be more easy in achieving the 500-calorie threshold than cutting your intake of food by 500 calories only.)

The thing is, you don't need to be going overboard 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. The recommended limit is 1,000 calories a day, according to the NIH. If you're eating fewer calories, it could hinder weight loss and block your body from getting the nutrients it requires for a healthy lifestyle. If you eat too few calories even for just one day, you can feel feeling hungry, upset or fatigued and feel constipated or diarrhea. The issue is that it doesn't promote good eating habits that can be maintained. If you cut back on calories for a long amount of time (think: months) that could lead to malnutrition, nutritional deficiencies as well as result in you being in a state of starvation. Because of this, your body may hold on to fat as a means of reserve energy for your body which will in turn hinder the process of losing weight and be counterproductive to your goal.

A healthy rate of losing weight is 1 to two pounds over a week According to NIH. Anything more than that may lead to danger and the potential for health risks. A rapid weight loss is a strain on the body and can increase the risk of developing gall stones malnutrition and electrolyte imbalance and damage to the liver. If the weight loss rate is more than 1 to 2-pounds per week (i.e. after bariatric surgery) Then it must be monitored by a team of medical professionals.

It's important to remember that when you have an underlying medical issue that can be the cause of weight increasing (such as type 2 diabetes or hypothyroidism) try using an calorie deficit to reduce weight isn't always successful. That's why it is important to consult your physician when you've recently gained a large amount of weight or you've been trying to shed weight but haven't succeeded.

Short-term 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." However, after six months of utilizing an calorie deficit to shed pounds it's crucial to change to a weight-maintenance plan - regardless of whether or not you've succeeded in achieving your goal according to National Institutes of Health. If you've lost weight, maintaining it is extremely difficult. Therefore, taking breaks for a few weeks or even months to make sure you don't return to it will help you maintain your weight loss in the long run. Based on the Transtheoretical Model (or Stages of Change) utilized to explain behavior changes, the fifth stage is the maintenance phase where the behavior is sustained (for at least six months) and is intended to be maintained throughout the future. Entering this maintenance mode after several months of a calorie deficit isn't necessarily about what you're eating and allowing yourself the time to keep up with your behaviour changes. Based according to this method, six-months tends to be the magic number. Once you've been off the weight for several months, you'll be able to recalculate your calorie requirements and then create an additional deficit in order to continue your effort to lose weight.

On that note, when you hit a plateau in your weight loss -- which is a thing that happens and is an inevitable part of the weight loss process -- it's essential to evaluate your calorie requirements since a second deficit (though maybe not as large) could be required. For instance, if you lost 10 pounds by eating 500 calories less every day for a period of about 2 months then your calorie needs will be less as you're now 10 pounds lighter. In this case, you'll have to reconsider your calorie needs based on your BMR and your level of exercise; you may end up having 750 calories less the day you began.

In the same way, once your weight loss goal has been met, you'll need to change your calorie intake accordingly. Being physically active on a regularly scheduled basis can assist in maintaining your weight loss by increasing your overall calorie burn (as well as also provide your body with tons of other health benefits).

The ultimate goal is to stay in the weight loss for a long period of time and not be able to see your weight climb back up. This is the reason why the NIH recommends no more than 500 to 1,000 calorie deficit per day. "The trick is to create small calorie deficits so that the weight you lose doesn't come back," explains Elizabeth Ward, M.S., R.D., author of Better is the New Perfect. If you are trying to maintain a large calorie deficit, you'll be extremely hungry and will not adhere to your diet plan for any length of time, effectively stopping your efforts to lose weight. The long-term, sustained loss of weight is much more challenging than losing weight, according to a report from 2019. In a meta-analysis of 29 long-term studies of weight loss More than half the weight lost was recovered in two years. In the following 5 years, more than 80 percent of the weight lost was recovered.

Calorie Deficit and Exercise

Individuals who are extremely physically engaged may be wondering if can shed pounds through 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," says Goodson. "Consuming too few calories can have a negative impact on performance and energy levels." For instance, if you're taking fewer calories or are exercising vigorously, you might be in danger of contracting female athlete triad syndrome, which manifests as menstrual cycle disturbances and energy loss.

"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 recommendation for people to cut down on their caloric intake , and then increase their activity level to create a caloric deficit. But if you're an athlete (think that you're running a marathon or another event that is strenuous), or perhaps have lot of weight to lose it's best to consult an experienced registered dietitian with a specialization in sports.

Behavior Change

The reduction in calories and exercising more is just half the combat. The NIH recommends that you engage in behavior therapy in conjunction with reduction in weight and physical exercise. As per the Transtheoretical Model (or Stages of Change), once the behavior is sustained over a period of more than six months after which it turns into something that people are able to follow. The creation of healthy habits that will last a lifetime are the ultimate goal in order to shed the weight.

Salge Blake recommends meeting with an registered dietitian nutritionist (RDN) who specializes in this field to assist you along the weight-loss journey. This service could be covered by your insurance. It is possible to locate an RDN near you by going to the Academy of Nutrition and Dietetics website and then clicking on "Find an Expert."

Why a Calorie Deficit Doesn't Always Work

The result of a calorie deficit can cause weight loss, but "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 that count calories can underestimate. This can make trying to shed weight through physical activities -- or formulating your calorie deficit needs , and then accounting for calories burnt during exercising more difficult.

If you're trying track your calorie gap, Salge Blake recommends using one of the many available weight loss applications to help keep track of the food you're eating. Remember "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 requirements and get the nutrients necessary to keep your body healthy it is important to concentrate on consumption of nutrient-rich food items and to limit foods high in saturated fat and added sugars. The 2020-2025 guidelines for dietary recommendations for Americans provides the 85/15 rule for guidance, where 85 percent of the calories consumed must come from sources that are rich in nutrients, and 15 percent could come from sources that are not calorie dense, such as those high in sugars, saturated fats and added sugars (think: cookies, candy or butter). (Related: These 5 Simple Nutrition Guidelines Are Undisputed By Experts and Research)

Additionally, if have any history of eating disorders (such as anorexia or nervosa orthorexia, or bulimia), you may not be a suitable applicant for calorie counting since the tedious character of calorie counting can lead to some kind of repeat relapse. Furthermore, those suffering from eating disorders spend many months or years relearning proper eating habits and work on eliminating eating disorders, which includes calorie counting. According to a study from 2010 published in the Journal of Neuroscience, calorie restriction can lead to anxiety and eating disorders even among those who do not have any history of eating disorder. (Related: Counting Calories Helped Me Lose Weight--But Then I Developed an Eating Disorder)

The Bottom Line

Using to create a calorie deficit to shed weight is certainly a technique that works, but not alone. Increased exercise, knowing how to assess what you eat (like portions) and a change in behavior towards sustainable and healthy eating practices are also part of the strategy. While many have tried this on their own, having the guidance of an RDN can certainly help with encouragement and motivation to achieve healthy weight loss goals.