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Calorie intake for fast weight loss: Diet for rapid weight loss: MedlinePlus Medical Encyclopedia

Diet for rapid weight loss: MedlinePlus Medical Encyclopedia

Rapid weight loss diet is a type of diet in which you lose more than 2 pounds (1 kilogram, kg) a week over several weeks. To lose weight this quickly you eat very few calories.

These diets are most often chosen by people with obesity who want to lose weight quickly. These diets are less commonly recommended by health care providers. People on these diets should be followed closely by a provider. Rapid weight loss may not be safe for some people to do on their own.

These diets are only to be used for a short time and are usually not recommended for more than several weeks. The types of rapid weight loss diets are described below.

People who lose weight very quickly are much more likely to regain the weight over time than people who lose weight slowly through less drastic diet changes and physical activity. The weight loss is a bigger stress for the body, and the hormonal response to the weight loss is much stronger. The hormonal response is one of the reasons that weight loss slows down over time and also why weight gain occurs when the diet is stopped or relaxed.

On a VLCD, you may have as few as 800 calories a day and may lose up to 3 to 5 pounds (1.5 to 2 kg) week. Most VLCDs use meal replacements, such as formulas, soups, shakes, and bars instead of regular meals. This helps ensure that you get all of the nutrients you need each day.

A VLCD is only recommended for adults who have obesity and need to lose weight for health reasons. These diets are often used before weight-loss surgery. You should only use a VLCD with the help of your provider. Most experts do not recommend using a VLCD for more than 12 weeks.

These diets usually allow about 1,000 to 1,200 calories a day for women and 1,200 to 1,600 calories a day for men. An LCD is a better choice than a VLCD for most people who want to lose weight quickly. But you should still be supervised by a provider. You will not lose weight as fast with an LCD, but you can lose just as much weight with a VLCD.

An LCD may use a mix of meal replacements and regular food. This makes it easier to follow than a VLCD.

This diet strategy is becoming more popular. It is often compared to fasting, but the two strategies are slightly different. Time-restricted eating limits the number of hours per day that you can eat. A popular strategy is the 16:8. For this diet, you have to eat all of your meals during an 8 hour period, for example, 10 am to 6 pm. The rest of the time you cannot eat anything. There are some studies that this method can cause rapid weight loss, but there is little information so far about whether the weight loss is sustained.

Fasting is an ancient form of caloric restriction. It has become more popular recently. This is partly because some animal and human studies have shown benefits to fasting for people with diabetes and obesity. There are many different fasting regimens and it is unclear which may be the best. One of the most popular is the 5:2 system. This involves 2 days a week of fasting or VLCD and 5 days a week of eating your normal diet. Diets that incorporate fasting can cause rapid weight loss.

Some fad diets also severely limit calories to achieve rapid weight loss. In some cases, these diets are not safe. In most cases, these diets are not sustainable for long enough to cause long-term weight loss. Once you stop the diet, you are at risk for regaining the weight if you return to your old eating habits. For most people, it is safest to choose a diet in which you lose a 1/2 pound to 1 pound (225 grams to 500 grams) a week.

Rapid weight loss is more about cutting calories than exercising. Talk with your provider about what type of exercise you should do while you are on this type of diet. Your provider may suggest waiting until you are on a more long-term diet to start exercising.

Rapid weight loss diet is usually for people who have health problems because of obesity. For these people, losing a lot of weight quickly can help improve:

  • Diabetes
  • High cholesterol
  • High blood pressure

You should only follow one of these diets with the help of your provider. Losing more than 1 or 2 pounds (0.5 to 1 kg) a week is not safe for most people. It can cause you to lose muscle, water, and bone density. Rapid weight loss can also cause some side effects including:

  • Gallstones
  • Gout
  • Fatigue
  • Constipation
  • Diarrhea
  • Nausea

People who lose weight quickly are also more likely to gain back the weight quickly. This can lead to other health problems.

In general, a rapid weight loss diet is not safe for children. It may also not be safe for teens, pregnant women or older adults unless a provider recommends it.

If you have a health condition, it is a good idea to talk with your provider before starting this or any diet plan to lose weight.

Very low-calorie diet; VLCD; Low-calorie diet; LCD; Very low energy diet; Weight loss – rapid weight loss; Overweight – rapid weight loss; Obesity – rapid weight loss; Diet – rapid weight loss; Intermittent fasting – rapid weight loss; Time-restricted eating – rapid weight loss

  • Yo-yo dieting
  • Weight loss

Academy of Nutrition and Dietetics website. 4 ways low-calorie diets can sabotage your health. www.eatright.org/health/wellness/weight-and-body-positivity/4-ways-low-calorie-diets-can-sabotage-your-health. Updated January 24, 2022. Accessed January 11, 2023.

Academy of Nutrition and Dietetics website. Staying away from fad diets. www.eatright.org/health/wellness/diet-trends/staying-away-from-fad-diets. Updated April 13, 2021. Accessed January 11, 2023.

Flier EM. Obesity. In: Melmed S, Auchus RJ, Goldfine AB, Koenig RJ, Rosen CJ, eds. Williams Textbook of Endocrinology. 14th ed. Philadelphia, PA: Elsevier; 2020:chap 40.

Parretti HM, Jebb SA, Johns DJ, Lewis AL, Christian-Brown AM, Aveyard P. Clinical effectiveness of very-low-energy diets in the management of weight loss: a systematic review and meta-analysis of randomized controlled trials. Obes Rev. 2016;17(3):225-234. PMID: 26775902 pubmed.ncbi.nlm.nih.gov/26775902/.

Updated by: Sandeep K. Dhaliwal, MD, board-certified in Diabetes, Endocrinology, and Metabolism, Springfield, VA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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How Many Calories Should You Eat? Weight Loss Calculator

Your ideal calorie intake depends on things like age and activity level. Most cisgender females need at least 1,600 daily calories to maintain their weight, while cisgender males need at least 2,000. If you want to lose weight, eating less can help.

Reducing the number of calories you eat per day can be an effective weight loss method (1).

However, figuring out exactly how many calories you should eat can be tricky, as it depends on a variety of factors, including your age, sex, size, and activity level.

Below is a simple scientific calorie calculator, along with five evidence-based tips on how to sustainably reduce your calorie intake.

Enter your details in the calculator below to figure out how many calories you should be eating per day to either maintain or lose weight.

The calculator is based on the Mifflin-St Jeor equation and can provide an estimate of your calorie needs. It utilizes population data, as well as other factors, including genetics, medications, and lean body mass, that affect your calorie needs (2, 3).

How to use this calculator

This calculator uses your age, size, sex, and activity level to estimate the number of calories you should eat per day to maintain your weight.

You can adjust this number based on your goals if you’re trying to gain or lose weight.

Keep in mind that this tool only provides general guidance, as activity levels and many other factors influence your daily calorie needs. Thus, this calculator will likely provide a number that’s close to your calorie needs, but it’s not a perfect tool.

Your doctor or dietitian can offer more individualized advice on your ideal calorie intake, depending on your health status and goals.

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When trying to lose weight, it’s important to create a calorie deficit by consuming fewer calories than you normally do or by exercising more. Some people choose to combine the two, eating a little less while being more physically active (4).

Still, it’s important to ensure that you’re consuming enough nutrients, even if you’re trying to lose weight, or you risk developing nutritional deficiencies and metabolic changes that make long-term weight maintenance difficult (5, 6).

Here’s a closer look at how many calories you should eat based on recommendations from the U.S. Department of Agriculture’s (USDA’s) 2020–2025 Dietary Guidelines for Americans (7).

Females assigned at birth (FAABs)

AgeDaily calorie requirements
19–30 years1,800–2,400 calories
31–60 years1,600–2,200 calories
61+ years1,600–2,000 calories

Keep in mind that these estimates don’t apply to those who are pregnant or breastfeeding, as they’ll need significantly more calories.

Males assigned at birth (MAABs)

AgeDaily calorie requirements
19–30 years2,400–3,000 calories
31–60 years2,200–3,000 calories
61+ years2,000–2,600 calories

Men who are very active or have certain health conditions may require more calories. The number you need within these ranges also varies based on your height and weight.


AgeDaily calorie requirements
2–4 yearsMAAB: 1,000–1,600 calories
FAAB: 1,000–1,400 calories
5–8 yearsMAAB: 1,200–2,000 calories
FAAB: 1,200–1,800 calories
9–13 yearsMAAB: 1,600–2,600 calories
FAAB: 1,400–2,200 calories
14–18 yearsMale: 2,000–3,200 calories
FAAB: 1,800–2,400 calories

Keep in mind that cutting a child’s calorie intake may increase their risk of nutritional deficiencies, slow growth, and foster an unhealthy relationship with food or an eating disorder (8). Instead of counting calories, it’s best to encourage eating healthy, nutrient-dense foods.


The amount of calories that your body needs can vary depending on your age, sex, activity level, and body size.

Simply put, a calorie is a unit that measures energy. Calories are usually used to measure the energy content of foods and beverages.

To lose weight, you need to eat fewer calories than your body burns each day. Conversely, to gain weight, you need to consume more calories than you expend (1).

Keep in mind that while the “calories in, calories out” concept of weight loss may seem simple, many factors contribute to weight loss or the inability to lose weight, including medical diagnoses, hormonal changes, genetics, and age (9).


Calories are units that measure the energy content of foods and beverages. While many factors can influence weight loss, you generally need to eat fewer calories than you burn to lose weight.

Although decreasing the number of calories you consume can be effective for weight loss, cutting calories without considering which foods you eat isn’t a sustainable way to lose weight.

Here are five simple strategies that may help you lose weight.

1. Eat more protein

When it comes to losing weight, protein is incredibly important.

Studies show that increasing your intake of protein may help keep you full and curb your appetite (10, 11).

Protein may also help fight cravings. According to some research, high protein snacks help enhance feelings of fullness while decreasing hunger and appetite (12).

In addition to promoting weight loss, some research suggests that maintaining a high protein diet may prevent or reduce weight regain and help maintain muscle mass (13, 14).

Therefore, if you want to achieve long lasting, sustainable weight loss, consider increasing your protein intake by eating more eggs, meat, poultry, tofu, nuts, seeds, or legumes.

2. Limit sugary drinks

Another relatively easy change you can make is to limit your intake of sugar-sweetened beverages, including sodas, fruit juices, chocolate milk, and other drinks with added sugar.

Your brain doesn’t register liquid calories the same way it does solid calories, so they affect your feelings of hunger and fullness less significantly (15).

Additionally, studies associate drinking sugary beverages with an increased risk of obesity (16, 17).

The harmful effects of sugar also go far beyond weight gain. In fact, added sugar may contribute to other health issues, including heart disease, liver problems, and type 2 diabetes (17).

3. Drink more water

One simple thing you can do for your health is to drink more water.

Adequate hydration is associated with improved brain health and weight management, as well as a reduced kidney stone risk (18).

What’s more, drinking water immediately before meals may reduce hunger and help you eat fewer calories (19, 20).

When combined with a healthy diet, drinking more water — especially before meals — appears to be helpful if you need to lose weight.

4. Exercise

Resistance-training activities like weightlifting have been shown to limit muscle loss, which may help minimize metabolic changes during long-term calorie restriction (21).

Cardio exercises, such as walking, swimming, or jogging, are also important — both for increasing weight loss and supporting overall health (22).

Additionally, exercise has a variety of other benefits that go beyond weight loss, such as increased longevity, enhanced energy levels, improved mental health, and a decreased risk of chronic disease (23, 24, 25, 26, 27, 28).

5. Reduce your intake of refined carbs and ultra-processed foods

The term “refined carbs” refers to grains that have lost their bran and germ, including white bread, pasta, crackers, and white rice. It also includes sugar and other sweeteners.

Refined grains typically lack fiber, which supports weight loss by decreasing your appetite and increasing feelings of fullness (29).

Eating fewer refined carbs may promote weight loss by altering levels of specific hormones that regulate your appetite, such as peptide YY (30). It’s also best to avoid ultra-processed foods.


Eating more protein, exercising, staying hydrated, and limiting your intake of refined carbs and sugary beverages are a few simple ways to decrease your daily calorie intake.

In addition to cutting calories, there are several steps you can take to lose weight in a sustainable, long lasting manner:

  • Practice mindful eating. Mindful eating can help reduce food cravings and promote long-term weight loss (31).
  • Eat more fruits and vegetables. Fruits and veggies are low in calories but high in fiber, which makes them ideal for weight loss (32, 33).
  • Stock up on healthy foods. Following a healthy diet is much more challenging when you have a kitchen full of processed foods. Make sure you have healthy snacks and foods on hand.
  • Find support. Studies show that social support may aid weight loss (34).
  • Try meal prepping. Many people find that meal prepping is a convenient way to eat well and save time.


In addition to decreasing your daily calorie intake, the tips outlined above may support long-term weight loss.

Although counting calories can be an effective strategy for weight loss, it’s important to remember that there are many other factors to consider when choosing what and how to eat.

Instead of focusing solely on calories, it’s best to follow a balanced diet that’s rich in a variety of nutritious, whole foods.

If you do decide to cut calories, be careful not to decrease your intake too much, as doing so may cause several serious side effects (4).

Research shows that young adults who use calorie-tracking apps to monitor how many calories they consume may be more at risk for developing disordered eating patterns that could develop into eating disorders (36).

That said, for people who are not at risk for developing disordered eating habits, restricting how much you eat can be a successful weight loss strategy, at least in the short term (37). However, eating too few calories may also slow your metabolism, making it harder to maintain weight loss in the long term (5).


Cutting calories too much may harm your health and make it harder to maintain weight loss. Instead of focusing only on calories, concentrate on a well-rounded diet that’s rich in nutritious, whole foods.

Are 1200 calories enough for a day?

Although it may help you lose weight, eating 1200 calories or less a day does not provide enough energy or nutrients for most healthy adults.

How many calories should you eat for breakfast?

The number of calories that you should eat for breakfast depends on many factors, including your daily needs, personal preferences, health goals, and overall diet.

How many calories should you eat for lunch or dinner?

While some people may enjoy eating a large lunch and smaller dinner, others may decide to distribute their calorie intake more evenly. Therefore, everyone’s needs and preferences are different.

How many calories should you eat to gain muscle?

To gain muscle, you may have to increase your calorie needs by a few hundred calories per day. A sports dietitian can help you develop an appropriate plan (38).


The number of calories that you should eat at each meal or to reach a specific weight goal can differ. Therefore, it’s best to experiment to find what suits your needs.

How many calories you need per day depends on whether you want to maintain, lose, or gain weight, as well as various other factors, such as your sex, age, height, current weight, activity level, and metabolic health.

Many websites and apps can help you track your calorie intake. You can try using a calorie counter or tracker for at least a few days to see the amount of calories, carbs, protein, fat, fiber, vitamins, and minerals you’re eating.

That said, working with a registered dietitian (RD) can also help you gain, maintain, or lose weight while ensuring that your nutrient needs are being met.

Just one thing

Try this today: Preparing your own meals at home puts you in control of what’s on your plate and makes it much easier to manage your calorie intake. It’s also a great way to control portion sizes and make healthy swaps using your favorite nutritious ingredients.

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How many calories do you need per day to lose weight? Calorie calculator online. Daily calorie intake for weight loss

Calorie counting is the most effective method of losing weight. When used correctly, it can give 100% results. Knowing the individual daily calorie intake, you can adjust the diet and achieve your goals faster.

Parameters affecting the choice of diet

The diet should be based on the characteristics of the body and the required amount of nutrients. To calculate how many calories you need per day, consider:

  • daily activity level;
  • age and gender, since men need to consume more calories than women;
  • availability of training;
  • figure parameters, which include height and weight;
  • habitual diet.

Calculate how many calories you need per day to lose weight, you can do it yourself using formulas or using an online calculator. For example, nutritionist Lidia Ionova not only explains each step in the calorie counting formula, but also teaches how to build a food pyramid. And the American doctor Holly Phillips is convinced that by finding out how many calories you need to eat per day, you can get rid of fatigue.

Thus, having the necessary calculations in hand and knowing how many calories you need to eat per day, you can adjust your diet and achieve the expected results faster.

Women’s and Men’s Daily Calorie Values ​​

Fats, proteins, and carbohydrates are three key micronutrients that provide the body with the energy it needs and support biochemical processes.

The female body requires less daily calorie intake than the male body. This is due to the inherent genetic ability to quickly gain weight for full-fledged procreation.

The norm of kcal per day for a woman is on average about 2000 kcal. If it is necessary to lose weight, 500 kcal or 10-20% are taken away from the calorie norm for different age groups of women with different activities and diets.

At the same time, the number of calories per day should be reduced gradually, otherwise a sharp decrease in the intake of substances necessary for the body can cause menstrual irregularities, a weakened immune system, slow metabolism or problems with the heart.

Table 1. Daily requirement for proteins, fats, carbohydrates and calories of able-bodied men and women

Group Age, years Men Women
Proteins, g Fat, g Carbohydrates, g Energy, thousand kJ Proteins, g Fat, g Carbohydrates, g Energy, thousand kJ
Total incl. animals Total incl. animals
Predominantly knowledge workers 18-29 91 50 103 378 11.7 78 43 88 324 10.1
30-39 88 48 99 365 11.3 75 41 84 310 9.6
40-59 83 46 93 344 10.7 72 40 81 297 9.2
Light manual workers 18-29 90 49 110 412 12. 6 77 42 93 351 10.7
30-39 87 48 106 399 12.2 74 41 90 337 10.3
40-59 82 45 101 378 11.5 70 39 86 323 9.8
Medium duty workers 18-29 96 53 117 440 13.4 81 45 99 371 11. 3
30-39 93 51 114 426 13.0 78 43 95 358 10.9
40-59 88 48 108 406 12.4 75 41 92 344 10.5
Heavy manual workers 18-29 102 56 136 518 15.5 87 48 116 441 13.2
30-39 99 54 132 504 15. 1 84 46 112 427 12.8
40-59 95 52 126 483 14.5 80 44 106 406 12.2
Workers engaged in particularly hard physical labor 18-29 118 65 158 602 18.0
30-39 113 62 150 574 17.2
40-59 107 59 143 546 16. 3

1. The need for pregnant women (5-9 months of pregnancy) is on average 12.2 thousand kJ, protein – 100 g per day, including 60 g of animal origin.
2. The need for nursing mothers is on average 13.4 thousand kJ, protein – 112 g per day, including 67 g of animal origin.

In order to determine how many calories a day a man needs, it is necessary to take into account that they have an accelerated metabolism and are prone to rapid weight loss. Therefore, the diet for the representatives of the masculine gender should consist of a diverse set of products.

The average calorie intake per day for a man is 2400 kcal and may fluctuate due to age, intensity of exercise, lifestyle and weight. To lose weight, men, like women, need to consume 10-20% fewer calories than the prescribed norm.

The daily requirement for calories, as well as carbohydrates, proteins, fats for able-bodied women and men is presented in the table:

How many calories do you need to lose weight?

In order for the body to activate defense mechanisms by slowing down the metabolism, it is necessary to understand exactly what calorie deficit is needed for weight loss. Experienced nutritionists advise to calculate how many calories a person needs per day, and then subtract 10-25% from the results. More detailed calculations are given by Elena Morozova, a doctor and founder of the Slavic Clinic. She warns against reducing the daily intake to 1000 kcal, which often occurs on low-calorie diets.

It is important not to reduce the calorie content of the daily menu below the requirements of the basic metabolism, since such a process of losing weight will be accompanied by loss of muscle mass and general discomfort.

You can create a 40% daily calorie deficit for weight loss in a very fast way. But it should be remembered that the safe calorie limit without the supervision of a nutritionist and a doctor is 1800 kcal for men and 1200 kcal for women. Otherwise, a person will not only lose weight, but will reduce immunity and simply deplete his body. But for a short period of time, you can stick to a diet even for 1000 kcal, says the author of cookbooks Ekaterina Maslova – and gives a menu for quick weight loss for a week.

Calculating your daily calorie intake can be done quickly and easily using the online calorie calculator, which can be found on almost any website dedicated to nutrition or healthy eating.

Online Calorie Calculator

Daily Calorie Calculator per day will help you find out:

  • how many calories you need to eat per day for the body to function normally;
  • how many calories do you need to lose weight;
  • how many calories it takes to gain weight.

To calculate calories for weight loss, you must enter your height, weight, sex, age, level of physical activity. You don’t need to do anything else, the online calculator will do everything by itself.

Age: years

Gender: Male Female

Weight: kg

Height: cm

Activity: minimal/no physical activityBasic metabolism3 times a week5 times a week5 times a week (intensive)Every dayEvery day intensively or twice a day Daily physical activity+physical work

Formula: Mifflin – San Jeor Harris-Benedict

The calculation of daily calorie intake can be made using two different methods: one of the most modern, according to the Mifflin-St. Geor formula, derived in 2005, and according to the older, but popular among nutritionists in our time, the Harris-Benedict formula, known since 1919.

Drying the body

Drying the body is a set of actions, the implementation of which reduces the percentage of adipose tissue in the body, maximizes muscle relief, and also burns subcutaneous fat.

Drying the body for girls and men consists in cutting carbohydrates in the diet, drinking more water, increasing the consumption of high-protein foods and sports nutrition.

According to the advice of experienced nutritionists and trainers, in order to saturate the body with useful elements with protein, it is necessary to consume vegetables and fiber, as they combine perfectly and enhance the assimilation of each other.

To draw up the correct diet, you should calculate the BJU online using a calculator. Thus, you can find out not only the individual need for calories, but also the necessary ratio of proteins, fats, carbohydrates, based on the goal pursued.

The application of knowledge about proper nutrition and diet planning is one of the main factors influencing the process of weight loss. The effectiveness of losing weight depends on many circumstances, but only a comprehensive approach to the existing problem will help to solve it effectively.

Count calories and lose weight. Body Mass Index Calculator

Why can some people eat whatever their heart desires and never get fat, while others only need to sniff an extra bun, and the hated fat on the tummy is right there? It’s just how our life is arranged, this is how the metabolism works: the calories consumed are burned without a trace or accumulate in the body – and there is no third way.

Calorie calculator for weight loss online

Disappointing conclusion number one: there are lucky people in the world who can safely score on losing weight and counting calories.

Are you one of those lucky ones? Then read on to find out. And to learn to use this rule every day.

Positive conclusion number two: If you want to control weight, count calories!

Do it every day, without breaks and days off! You ask, is it possible to lose weight without daily calorie counting? We answer: yes, you can, but only for a short time. Because then all the lost kilograms will come back, and they will even take a couple of extra ones with them. Familiar story? That’s it! It turns out so because, while on a diet, we limit ourselves in food. The body does not like it – it does not receive the substances it needs, it experiences stress. He starts to panic and then, at the end of a low-calorie diet, actively accumulates fat, otherwise, God forbid, starve again.

So what does give you daily calorie count ?

Slimness: you will start to like your own reflection in the mirror
Health: you will forget about doctors and pills
Youth: your body will look younger and full of energy

So you need to count calories, but how to do it right ?

First, let’s figure out what “calories” are. And this is nothing but energy for our body. Calories enter our body with food and are spent for their intended purpose. That is, the body “burns calories”, using them for physical and mental activity. And those calories that are not consumed by him remain in the body “for a rainy day”, in reserve – already in the form of fats. And the lack of calories provokes the body to more active weight gain (plus it also leads to malaise and weakness). What follows from this? –

Life-affirming conclusion number three: In order not to provoke the body to gain excess weight, you need to know your daily calorie intake and maintain a balance of calories.

If you are interested not in a one-time result, but in a long-term one, if you want to maintain health and youth, then calorie counting will be the only right choice on the way to an ideal figure.

Everyone has their own daily calorie intake, it depends on many factors: age, gender, weight, height, lifestyle, as well as individual characteristics of the body. Our online weight loss calorie calculator will help you determine exactly how many calories you need per day to stay slim.

Calorie counter online will help both women and men. With it, you can:

– reduce weight correctly

– gain weight correctly

– maintain optimal weight

The daily calorie intake depends on the goal.

Although our weight loss calorie calculator is very accurate, remember that the error in the results can be quite high . This is due to the fact that it is impossible to determine with 100% accuracy the rate of calorie burning by your body. To minimize errors, we suggest using the online calorie counter in this way:

1. Start losing weight or gaining weight with the daily calorie content that the calculator suggested.

2. If weight loss does not decrease after one or two weeks, reduce your daily caloric intake by 100-200 calories. Continue lowering until your body weight begins to drop.