If I eat 400 calories a day how many calories do I need to burn a day in order to lose 20 pds in 3 weeks?

Answer 1

400 calories a day is way too little.

Answer 2

Well, if you were to lay down all day, without doing anything, just to live, your body will burn about 1200 calories. Guessing that you don't just lay down ALL day in your house, you would have to eat MORE than 1200 calories, or else your body will go into starvation mode = weight gain.

If you only eat 400 calories, you will definently lose weight, but you'll gain it back, plus MORE weight on top of that. That's just the way our bodies work. Don't go under 1200. Just eat upto 1200 (If your extremely overweight, and your doctor said you could) every day, and burn calories from there. Eating too few calories can cause major problems because our body needs food to work right. (Believe me, I would know. I only ate about 200-300 calories for 3 months, and had lung problems, and I was extremely depressed).

Now, to losew eight a good way, eat a balanced healthy diet, and exercise. Don't try using a scale, but use a measuring tape instead. Losing inches > losing weight.

Try eating organic, all natural, whole grain foods, in reasonable portions, and workout/ and do some cardio atleast 3 times a week. It may take a while to see results, but it's a healthy way of doing it, and the results will look great if you stick to it.

Answer 3

You'll never make it. If you only eat 400 calories a day you'll bottom out your blood sugar and will end up on a binge in a week. Your body will go into starvation mode and will stubbornly refuse to lose weight. Go for 1000 calories--which is the minimum for any healthy diet--and start exercising 5 days a week. Drink 2 quarts of water a day, plus take a multivitamin everyday, and stay away from all things caffeinated or carbonated. Stick with lean proteins, at least 2 citric fruits, and load up on green vegetables.

Answer 4

20 pounds in 3 weeks is an unrealistic goal. Eating fewer than 1200 calories per day works against your efforts to lose weight because it causes the body to shift into starvation metabolism, which means that almost all food is converted to fat and retained. You will lose muscle mass and end up fatter and weaker than before, with a sluggish metabolism.

First you need to set a realistic goal. One or two pounds a week is attainable. Second, you need to find a diet plan that fits your lifestyle and teaches you how to maintain your weight for life. Weight Watchers is a good choice, or, consult a registered dietitian for a personalized program. Third, you need to include exercise in the mix. Choose an activity you enjoy doing, and you will have greater success staying with it. A combination of cardio and weight training provides the quickest, most effective results.

Answer 5

To lose 20 lbs in 3 weeks you need to burn 3334 calories per day. So, if you are eating 400 calories you need to work off 3734 calories. Most people burn 2000 calories just by being awake, so you need 1700 calories from exercise PER DAY.

I just want to say, that maybe you should extend your time period. I think it's extrememly unhealthy to expect to lose 20 lbs in under 6 weeks.

400 calories a day isn't enough nutrition at all. I can't see how you could possibly get all the nutrients and amino acids you need on that.

If you do attempt this, please at least take a multi-vitamin with potassium and eat very nutrient rich foods (spinach, carrots, sweet potatoes, nuts, berries)

Answer 6

You probably want a mathematical answer to your problem. Sure, I could do that for you, but why not keep it simple. Indulge me a little and check out this simple plan that can work for anybody. There are basic secrets to nutrition and fitness.

The secret is acknowledging the true purpose of food as fuel rather than entertainment. Focus on protein, fats, and carbohydrates and learn about each of them. A little bit of research online will teach you a lot. Remember, don't diet; change your eating lifestyle. Doing so will change your life for the better. For the exercise, consider it a priority to include it into your routine.

Anyway, if you want it simple, here it is in ten steps:
1. protein is good...eat plenty (about 30% of your caloric intake)
2. fats are good and bad...know the difference
3. saturated and trans fats are the bad ones - limit these
4. poly- and mono-unsaturated fats are good - don't be afraid of them
5. carbohydrates are good and bad...know the difference
6. fibers and complex carbs are the good ones - eat these (about 40% of your caloric intake)
7. sugars and simple carbs are the bad ones - limit these, particularly late in the day (stay away from sodas and chips!)
8. drink water - lots and lots and lots of water. It's the only drink you need. Anything else is either wasted or simply bad for you
9. Eat 4-6 "meals" a day to boost your metabolism.
10. A meal is defined as a portion of a low-fat, protein rich entree, a portion of veggies for vits/mins, and a portion of complex carbs. (You can get these combined as a health shake)

For exercise, it's even simpler:
1. 4-6 hours per week
2. 45-90 min each day you exercise
3. do aerobic exercise (20-40 min) every day you exercise
4. work abdominals every day you exercise (between sets makes it easy)
5. do chest and triceps exercises on one day
6. do back and biceps exercises on a different day
7. do legs and shoulder exercises on a different day
8. do your exercises in sets (i.e. 3 times with 6-12 repetitions each)
9. keep a record of what you do to measure progress.
10. when your progress stalls (called "plateau"), switch up your routine.

Okay, now since you indulged me, I'll give you your mathematical answer. To burn ONE pound of fat, you must burn 3500 EXCESS calories. Excess calories are the difference between what you consume and what you need and can be considered what you burn when you exercise, since you didn't metabolise those calories. Your goal in math terms: 20 lbs x 3500 calores = 70,000 excess calories. Do burn at this intensity over a three week period will likely be very unhealthy for you. As such, it is an unrealistic goal. Instead, don't track the calories....don't weigh yourself. Just follow the steps above and check yourself after TWELVE weeks. If you stick to it, you'll be amazed at your transformation.

Answer 7

I have set myself to loose that amount but over a period of five/six months not three weeks!!
if you drop down to 400 calories a day your body will think you are starving it and metabolic rate will fall and you will GAIN weight trust me tried to crash diet and end result bad tired all the while grumpy and ended up putting more back on.
I am doing low fat diet, regular eating (did not do before) and excersise and have lost 5 pounds in just under three weeks i am happy with that as not only is it coming of slow it will stay off but best of all i am loosing inches more and clothes are getting loose also body starting to tone.
Please be carefull if you go to mad some damage may be irriversable.

Answer 8

you can safely lose 2lbs a week. losing more than that means you will be very likely to put the weight back on as soon as you increase your calorie intake.

400 calories is way too little. eat 1500 calories and do cv 3-5 times a week. that is the best way to lose weight. also you will need a balanced diet (low in fat though). also avoid carbohydrates after 6pm

Answer 9

If you only eat 400 calories a day,your hair and teeth and bones, heart muscles, liver, kidneys will be starved. They will have to go to lean muscle mass to get the protein it requires to function. You interfere with the basic integrity of these muscles-organ functions, and then you'll be thin, but have a heart attack? If you want to lose 20 pounds in 3 wks, you should cut off a limb. That's ll lighten you up. Losing weight takes time. If it took you 2 years to get 20 fatter, than it'll take 2 years to lose it. but..good luck in this dangerous pursuit.

Answer 10

i think like so.many anybody is uneducated abouf how our bodies artwork. hunger mode is a debatable subject count. If this have been real human beings in poverty countries does no longer be so skinny..theres been.experiments that cancels the hunger mode concept. unwell say from own adventure, I lost 30 lbs in a sprint over 30 days yet ingesting 500 energy an afternoon and approximately an.hr of work out a pair circumstances a week. Im engaged on dropping 30 extra lbs by making use of my birthday in 3 weeks.

Answer 11

400 cals a day isn't even sufficient for a newborn baby let alone a child or adult that is physically active. on such a low caloric intake the body will be in starvation mode, it will hold onto it's fat stores and metabolize nutrients from stored muscle proteins and carbohydrates (glycogen) for energy. you will lose mainly water weight from the reduced intake of carbs and some muscle. you very well may end up with a higher level of body fat at the end of your "diet" than before.

starving the body is the absolute worst way to lose "weight" and does nothing except disrupt the metabolism and endocrine system.