Imagine if you suddenly stopped eating. What would happen to your body? Just like a campfire needs wood to burn and a car needs fuel to run, your body needs food to function. Let’s explore what happens when you stop eating and how your body reacts.
To understand what happens when you stop eating, it’s important to know what happens when you do eat. It all starts with the sun. Plants use sunlight to create energy through photosynthesis. When you eat plants, like tomatoes, or animals that have eaten plants, like chickens, you’re consuming that stored energy.
Take a hamburger, for example. It provides fats from sauces, proteins from the beef patty, and carbohydrates from the bun. Your digestive system breaks down these components using chewing, stomach acids, and enzymes. The nutrients are then absorbed into your bloodstream. Excess glucose is stored in your liver and muscles as glycogen, and some is converted into fats, which you can see in the softer parts of your body.
Your body has about 37 trillion cells, and they get energy from food in the mitochondria. Here, glucose and fats are transformed into Acetyl CoA and enter the citric acid cycle, releasing energy-carrying molecules. This energy helps pump protons in the mitochondria, creating a dense area that protons want to leave. They exit through a protein called ATP synthase, producing ATP, your body’s main energy source. You use around 10²⁵ ATP molecules daily.
When ATP is converted to ADP, energy is released for your body’s needs. If you stop eating, within six hours, your body starts using glycogen and fats to keep functioning. This is normal, but after 72 hours, your body begins breaking down proteins to make glucose from amino acids, as fats can’t cross the blood-brain barrier to fuel your brain.
Without vitamins and minerals, you might start feeling unwell within a week. After several weeks, your fat reserves deplete, and your body uses proteins for energy. This includes essential proteins like antibodies and muscle proteins, leading to serious health issues.
Death from starvation can occur between three weeks to 70 days, often due to heart problems from tissue breakdown. Survival depends on hydration and initial fat reserves. While it’s fascinating that you could survive up to 70 days without food, it’s crucial not to try this.
If you’re interested in learning more about food and other topics, check out Skillshare. They supported this video and offer a two-month free trial to the first thousand people who sign up. Skillshare is an online community with over 17,000 classes in design, photography, cooking, and more. You can take classes, try projects, and even teach your own class. With a premium membership starting at $10 a month, you get unlimited access. Visit the link in the description to learn more and subscribe for weekly science videos every Thursday.
Research the roles of carbohydrates, proteins, and fats in the body. Create a presentation that explains how each nutrient contributes to energy production and overall health. Include diagrams of the digestive process and how nutrients are absorbed and utilized.
Create a 3D model of a mitochondrion using craft materials. Label the parts involved in the citric acid cycle and ATP production. Present your model to the class, explaining how energy is generated and why ATP is crucial for cellular functions.
Analyze a historical or contemporary case study of starvation. Discuss the physiological changes that occur during prolonged food deprivation and the impact on health. Present your findings in a report, highlighting the importance of balanced nutrition.
Participate in a class debate on the ethics and health implications of fasting. Research different perspectives, including religious, medical, and personal viewpoints. Prepare arguments for and against fasting, considering both short-term and long-term effects.
Conduct a week-long experiment where you track your energy levels based on your diet. Keep a food diary and note how different meals affect your energy and concentration. Present your findings to the class, discussing the relationship between diet and energy.
This episode is supported by Skillshare. Campfires need wood to release heat, cars need petroleum to move, and you need food to fuel every aspect of your life. So what would happen to your body, right now, if you suddenly stopped eating food?
To understand what happens without food, we first need to understand what happens when you eat. It starts with the sun, whose energy is harvested by photosynthesis in plants. We then consume that stored chemical energy, either directly from eating plants like tomatoes or by eating animals like chickens that have eaten plants like grains.
If we take a hamburger as an example, you absorb fats from the sauces, proteins from the beef patty, and carbohydrates from the bun. Your digestive system uses processes like chewing, gastric acid, and enzymes to break the food into small enough molecules that you can then absorb into your bloodstream. Any excess glucose is stored in the liver and muscles as glycogen, while some is converted into fats. You can visually see some of the fat stores in the pudgier parts of your body.
There are around 37 trillion cells in your body, and you start to really harvest the energy from your food in the mitochondria of your cells. This is where glucose and fats are broken down into Acetyl CoA and go through the citric acid cycle, where they’re modified continuously to release energy-carrying molecules. The energy from these molecules is then used to pump protons into a layer of the mitochondria that becomes dense with protons, which need to diffuse back into the less busy space and do so by going through a protein called ATP synthase. As a result, ATP is created, the most important energy source in your body. You use around 10²⁵ molecules of ATP every day.
When this ATP is hydrolyzed into ADP in your body, the bond breaks, releasing energy for various biological processes. If you stopped consuming food, within 6 hours, your body would start breaking down glycogen into glucose and fats into Acetyl CoA to keep your biological processes functioning. This is quite normal, but after 72 hours, your body would need to start breaking down protein to synthesize glucose from amino acids; otherwise, your brain would be deprived of energy. This is because fats used for energy can’t cross the blood-brain barrier.
With no vitamins and minerals being consumed, people might start to feel unwell within a week. After several weeks of starvation, fat stores become depleted, and the body begins to use proteins for energy. At this point, essential proteins for survival, like antibodies used to fight infection or muscle proteins, are now being used to make glucose. This loss of protein can lead to severe health issues.
Death can occur as soon as 3 weeks to 70 days, commonly due to heart complications resulting from tissue degradation. A factor in how long you can survive is how hydrated you stay and how many fat stores you had to begin with. Although it’s remarkable to think that if you stopped eating today, you could potentially live for another 70 days, please do not attempt this.
If you love learning about food, you should definitely check out Skillshare, who supported this video and is offering a two-month free trial to the first one thousand followers who sign up. Skillshare is an online community for creators with more than 17,000 classes in design, photography, cooking, and more. Everyone can take a class, try a project, and even teach a class themselves, with premium membership as low as $10 a month for unlimited access. Just head to the link in the description, even on their mobile app, and subscribe for more weekly science videos every Thursday.
Food – Any nutritious substance that organisms consume to maintain life and growth. – A balanced diet includes a variety of foods to ensure the body receives all necessary nutrients.
Energy – The capacity to do work, which in biological systems is often derived from the metabolism of nutrients. – The mitochondria in cells convert glucose into energy that powers cellular functions.
Cells – The basic structural, functional, and biological units of all living organisms. – Red blood cells are responsible for transporting oxygen throughout the body.
Glucose – A simple sugar that is an important energy source in living organisms and a component of many carbohydrates. – During cellular respiration, glucose is broken down to release energy for cellular activities.
Proteins – Large molecules composed of amino acids, essential for the structure, function, and regulation of the body’s tissues and organs. – Enzymes, which are proteins, play a crucial role in speeding up biochemical reactions in the body.
Vitamins – Organic compounds that are essential in small quantities for normal metabolism and health. – Vitamin C is important for the repair of tissues and the enzymatic production of certain neurotransmitters.
Minerals – Inorganic elements that are necessary for the body to function properly and maintain health. – Calcium is a mineral that is vital for maintaining strong bones and teeth.
Starvation – A severe deficiency in caloric energy intake needed to maintain an organism’s life. – Prolonged starvation can lead to muscle wasting and organ failure.
Digestion – The process by which the body breaks down food into small nutrient molecules that can be absorbed into the bloodstream. – The digestion of carbohydrates begins in the mouth with the enzyme amylase.
Health – The state of complete physical, mental, and social well-being, not merely the absence of disease or infirmity. – Regular exercise and a balanced diet are essential for maintaining good health.
