How Long Can An Obese Person Survive Without Food?

How long can we survive without food in an emergency? And what if you have some extra pounds? Does that mean that you can last longer? How long can an obese person survive without food? This post is not meant to offend or shame anyone. I think this is a very practical question that we should investigate and find answers to. Also, keep in mind that every body is different and has different requirements.

In a survival situation, you may need to set your pride and feelings aside to survive. I am writing this post because I care about your survival. The good news is that if you happen to be seriously overweight or even obese, you may be surprised by how long you can survive before starvation hits. Especially if you have some multi-vitamins that you can take.

How long can an obese person survive without food?
How long can an obese person survive without food?

How long can an average person survive without food?

The average person can survive without food for approximately 21 days before starvation kicks in.

The general rule is that a person can survive 3 days without water and 3 weeks without food. However, each person has specific factors that will impact their personal experience. For example, your starting weight will play a role in your ability to survive without food. Additionally, your overall health, the environment, and the quality of food you consumed before all hell broke loose can also play a role. I was surprised to learn that the biggest factor has to do with hydration.

How long can an obese person survive without food?

A person has the potential to survive an additional 110 days for every 50 pounds of excess body fat. This depends on the individual’s hydration, exertion levels, and overall health. One documented case revealed that a 456 pound man survived 382 days without food and just the occasional vitamin supplement.

The body will burn fat for energy to keep itself alive during the starvation process. An overweight or obese person generally has significantly more fat cells than an average person. As a result, the stage of starvation can take longer and allow the overweight person to live much longer than the average person. There are additional factors including the amount of excess fat that determines how long an obese person will survive.

How Long Can You Actually Go Without Eating?

How long can an obese person survive without food?

The Starvation Process

A lot happens to your body when it is deprived of food. Let’s talk about the physiological process of starvation. Everyone generally starts out the same, but there comes a point in the process where obese people can really shine.

  • 12 hours following your last meal, you may experience mild stomach cramps similar to the gurgle of an empty belly. At this point, it is only as bad as waking up after sleeping in and feeling hungry. You might think about food a lot more, but it won’t be too dramatic.
  • 24 hours after your last meal, your stomach cramps will significantly increase. You might burp, feel nauseous, and obsessively think about food. Your mental acuity may decrease as a result of feeling distracted, but you will still be able to accomplish your important tasks. Your blood sugar might be low and you’ll probably feel cranky. It’s not fun, but you haven’t hit the panic button yet.
  • 48 hours after your last meal, your body will have depleted the last of the glycogen stores from your liver and muscles. You will feel agitated, fatigued, and unable to concentrate on complex tasks. You may feel unstable and shaky.

This is the transition period. A signal for your body to do something drastic.

  • Once the stored glycogen is depleted, your body will start to break down fat into ketones for fuel. The rate of fat usage will vary from person to person, but this stage can take months. At this point, being obese or a little overweight, can give you a significant advantage over a thin person.
  • If you have large fat stores, then you can survive at this stage for awhile. Unfortunately, your brain cells and red blood cells cannot utilize ketones so your body will begin to break down muscles.
  • Once the fat is gone, the only thing left to break down is muscle. Things get dire at this point. Your muscle tone will significantly decrease and you will have dropped a significant amount of weight.
  • After awhile, your cells will start to die from lack of proper nutrients. Accelerated cell death is bad news.
  • Your potassium levels will plummet and you will experience weakness and muscle spasms.
  • Cell death will compromise your immune system and make your vulnerable to infections and illnesses.
  • Your electrolytes will become unbalanced and this will make it harder for oxygen to reach your organs.
  • Once starvation sets in your muscles will atrophy (after 40-50% of your body weight is lost).
  • The beginning of the end will reveal itself in the forms of abdominal bloat, flaky skin, dehydration, hair color changes, and paralysis. At this point the immune system is all but destroyed and the ability to consume enough food to provide nutrients to your ravaged body is gone.

The Psychological Effects of Starvation

Now we must explore the psychological effects of starvation. Survival is already very stressful on the body, but mental and emotional stress can make matters worse when the threat of starvation is on the table. Possible effects could include:

  • Irritability
  • Depression
  • Thinking about food obsessively
  • Guilt
  • Confusion
  • Apathy
  • Elation / vindication
How long can an obese person survive without food?
How long can an obese person survive without food?

Ways that overweight people have an advantage

In general, seriously overweight or obese people can do better than Mr. Gymrat if there’s no food available in a survival situation. Science says that obesity gives us an advantage over super-fit or thin people when it comes to starvation. An example of this is the Ketogenic diet which forces your body to burn fat instead of carbohydrates.

If you show up to the apocalypse with some love handles, a spare tire, or even a full keg around your center, rejoice! Your body is better equipped to handle the rigors of starvation.

What do obese people have that thin people don’t? Fat!

There isn’t a hard and fast rule here because everyone’s fat to muscle ratio is different and everyone burns fat at different rates. If you look at your own personal stats, you can make some estimates. When your body switches to burning fat for fuel, we may infer that more fat equals a longer survival period. How did we estimate that a person can survive up to 110 days for every 50 pounds of excess body fat on their body?

Here’s the math: One pound of body fat equates to about 3,500 calories. If you burn 1,500 calories a day at rest, that’s approximately 2.3 days living off one pound of fat. If you have 50 pounds of extra fat, that comes out to over 110 days. Of course, there’s more to it, but that’s a good starting place for you.

Surviving Starvation Case Studies

Hunger strikes are not uncommon and they provide us insight on the capabilities of the human body. Mahatma Gandhi’s case was well-documented. He survived 21 days of starvation when he was in his 70s. Solange Fernex went for 40 days without food, while Cesar Chavez went for 36 days. Those aren’t even the longest instances, but I doubt that you and I will be taking part in hunger strikes after the apocalypse. What about involuntary starvation?

For a healthy adult, the saving grace could be as simple as finding a morsel of food and a few sips of water per day. For example, Rita Chretien survived in her vehicle for an impressive 48 days. She accomplished this by eating a very small amount of trail mix and drinking water from a nearby stream. She lost about 30 pounds as a result of her ordeal, but she survived.

All of these people survived starving in different circumstances, but there was one important similarity. Every story specifically mentions that the people had access to clean water. Even if you have plenty of food and medical care, dehydration can kill you in under a week. If you have to choose between hunting for food or finding water, search for water.

What is the longest that a person has survived without food?

This article from the “National Center for Biotechnology Information,” explores the case of a man who survived 382 days without food. The man in the study started out at 456 pounds and got down to 180 pounds at the end. This means that he lost a total of 276 pounds. He was monitored by doctors and given vitamin supplements, but that’s it.

The patient went 37 -48 days between bowel movements and suffered no known lasting ill-effects from the ordeal. In fact, 5 years after undertaking the fast, he still weighs 196 pounds.

There is a good reason why most bug out bags and prepper stashes include multivitamins and other supplements. With proper hydration, a decent store of body fat, long term survival on supplements alone could be possible.

If you have access to multivitamins and other supplements, you can greatly increase the odds of your survival when you can’t find food. Another bonus is that supplements are small, lightweight, and easy to carry with you while you search for food.

How to calculate how long you may be able to survive without food

It is possible to calculate how many days you could survive without food. You will need to estimate how many pounds of extra fat you are carrying and the total number of calories you expend in a day. This number is an approximation and should not be relied upon.

Step 1: Find out your TDEE (Total Daily Energy Expenditure) with this website. This will tell you how many calories your body burns per day just staying alive.

Step 2: Take the estimated amount of body fat you have and multiply it by 1,500. This number will be the approximate number of extra calories your body has in the form of fat reserves.

Step 3: Now, take the number of calories you have stored as fat and divide it by your TDEE number you got in step 1. This will be the approximate number of days of survival that your extra body fat will buy you.

Gain weight as a survival strategy?

I’m not going to recommend that preppers and survivalists should gain hundreds of extra pounds while waiting for the world to end, but we can’t deny the facts. As long as you are still able to get up and move, build your shelter, and hunt for food, carrying some extra weight won’t be a bad thing if you are ever faced with a situation where you can’t find food. Wait! Did I just suggest that you eat that tempting item on the menu? Maybe…

Carrying extra body fat may not be socially acceptable in our current fitness-obsessed society, but when it comes to survival, the extra fluff could help. Your extra fat can stabilize your metabolism and sustain you until you can find your next meal. A tiny rail-thin person with very little fat and weak muscles is not going survive as long as a beefy lumberjack with a big belly.

Again I’m not recommending that you pack on the pounds, but if you are thinking of gaining some weight for survival purposes, you would want to do it slowly and with quality foods. Here are some guidelines:
  • Eat fresh fruits, veggies, and protein/ lean meats
  • If you must have that cheeseburger and fries, enjoy it no more than once a week
  • Never neglect your fitness while aiming to put on weight. The last thing you need is to get so big so fast that you cannot complete your daily tasks.
  • Build muscles too. Even if you have extra fat, your body will break down muscles to feed your brain when it goes a long time without food.
  • Work on your flexibility and endurance while your gaining slow, steady weight. This will help you to reach your bug out location, carry your BOB, and build a shelter without having a heart attack.


How long can an obese person survive without food?

I think it’s safe to say that being overweight when you get lost in the woods or the world ends, is more likely to work in your favor than being super thin with a super low body fat percentage. However, this does not mean that we should all aim to become morbidly obese on the off chance that disaster will strike. I think that having a few extra pounds, especially when you are otherwise healthy isn’t a bad thing and may help you survive.

This article was meant to give you hope and provide you with some good news. I hope that it didn’t offend you, but provided you with some insight and motivation that will help you survive.

Did I just make you want to run out and get some dinner? What are your thoughts on starvation? Comment below!

See you next time!