What You Need To Know About Fasting, Starvation Diet, and Caloric Restriction

By Anthony Smith, PhD., Juvenon Science Advisor

Are fasting and a starvation diet the keys to losing weight? Find out more about it here.

RELATED: Tropical Fruits To Add To Your Diet ASAP

In this article:

  1. Research on Starvation, Caloric Restriction, and Fasting Diet
  2. Defining Starvation Diet and Other Similar Diets
  3. Starvation Diets (And How They Fail)
  4. Negative Effects of Starvation in the Long Run
  5. What Sets Intermittent Fasting Apart
  6. Sensible Weight Loss Strategies
  7. Crash Diets Can’t Get Rid of Toxins
  8. Healthy Eating Diet Plan

The Truth About A Starvation Diet Plan

Research on Starvation, Caloric Restriction, and Fasting Diet

Recently, conflicting information has emerged on the topic of fasting, starvation, and weight gain. On the one hand, there is the ‘starvation myth’ based on the theory that starving oneself to lose weight can cause weight gain.

However, on the other hand, there is now compelling new research showing the beneficial effects of caloric restriction, e.g., weight loss, decreased oxidative stress, inflammation, and increased longevity. In this month’s Juvenon Health Journal we will explore this trending topic and what the newest research reveals.

Defining Starvation Diet and Other Similar Diets

Senior man eating fresh salad | What You Need To Know About Fasting, Starvation Diet, and Caloric Restriction

The terms fasting, intermittent fasting, calorie restriction, and starvation are often used interchangeably.

But are they really different words for the same thing? Yes. And no.

In some sense, these terms are similar and describe aspects of the same thing. If you eat fewer calories than your body ‘burns’ each day, you will lose weight.

But the ways and means of fasting, starvation, and caloric restriction give rise to vastly different physiologic and metabolic outcomes– hence the confusion.

On the cellular level, the main target of fasting, restriction, and starvation is our mitochondria– the tiny metabolic engines that power every cell in our bodies. Mitochondria convert the chemical energy potential in food into electrical and mechanical energy for our bodies.

Mitochondria are very dynamic–-always changing in size, population, and energy potential in relation to our exercise, diet, and lifestyle.

Before continuing, let’s look at the subtle, yet important, differences between fasting, calorie restriction, and starvation as scientific terms.

Intermittent Fasting

Intermittent fasting (IF) is simply the practice of skipping food intake for specific periods of time, generally 18-36 hours a couple of times per week. Increased food intake may result after periods of IF, so there may be no overall reduction of calories.

Although it has garnered much media attention in recent months, intermittent fasting is by no means a ‘new’ concept. Indeed, intermittent fasting mimics the evolved aspects of our physiology.

Think about it this way: Paleolithic man almost certainly did not have access to daily 2,500 calorie diets rich in carbohydrates and fat.

It’s important to point out that intermittent fasting is technically not a form of starvation, which is defined as a temporary state of very low or no caloric intake.

RELATED: Intermittent Fasting Tips For Faster Results

Calorie Restriction

Caloric restriction (CR) refers to long- term 30 percent to 60 percent reduction of caloric intake and is generally undertaken in laboratory or research settings.

There is much published research, studying CR in rats, dogs, primates, and humans.

The key to CR is precise control of food intake and rigid, long term adherence to the CR regimen. CR is a form of mild starvation.

Research supports that if you reduce caloric intake for long periods of time, there will be significant weight loss. A host of other beneficial physiologic and metabolic endpoints are also reported to be improved.

However, reports also revealed that irritability, anxiety, and extreme cravings are also characteristic of CR. Therefore, the adaptation of a CR lifestyle outside of research settings seems impractical for all but the most obsessive personalities.

Starvation Diets (And How They Fail)

Tired middle-aged business woman in her office looking down | What You Need To Know About Fasting, Starvation Diet, and Caloric Restriction

From the grapefruit diet to the cabbage soup diet, temporary starvation or crash diets have long been popular with those who yearn to lose weight fast. There is no argument that starvation will result in weight loss.

But what happens when we induce a metabolic starvation mode? And why do crash diets fail?

Simply put, temporary starvation slows the metabolism. The basal metabolic rate declines and our physiology slows as well.

Not surprisingly, the dieter feels tired, sluggish and cranky.

Here’s what is occurring behind the scenes of that promising new crash diet. Since the body must start consuming its reserve energy (fat), it enters a period of extreme metabolic economy.

Since there is a metabolic fuel shortage, mitochondria tend to shrink and go ‘offline’ in the interest of preserving this economy. If you keep to starvation mode, long-term, through ingestion of a very-low-calorie diet, the metabolism rebounds and you enter the sort of metabolic state described in CR.

Typically, however, starvation mode ends and food intake is resumed. You might think, ‘hey, that doesn’t sound so bad for a dieter,’ but you’d be wrong and here’s why.

Under the context of starvation induced slow-metabolism, the first priority of our physiology is to restore the reserves that were consumed. So even resuming a ‘normal’ calorie diet after a short period of starvation will result in rapid weight gain.

Starvation also puts your health at risk with other possible complications such as vitamin and mineral deficiencies, hormonal imbalance and the potential for psychological and behavioral disorders related to food.

The starved state is characterized by extremely low blood glucose levels.

Negative Effects of Starvation in the Long Run

If we have fat reserves, it seems like starvation would be good, right? Well, it’s not so simple.

The heart and skeletal muscles are efficient users of mobilized fat energy, but the brain and central nervous system are strict metabolizers of glucose, not fat.

So, during the starved state, the body preferentially focuses its physiology on making glucose for the brain not mobilizing fat for the muscles. This keeps you alive, but muscle metabolism shrinks because mitochondria shrink in size and population.

This state is often referred to as a shrunken or slow metabolism and it can have a lasting negative impact on your health. Importantly, the altered metabolism makes it easy to gain weight and hard to lose weight in the future.

What Sets Intermittent Fasting Apart

Portrait of a beautiful older woman with green healthy food | What You Need To Know About Fasting, Starvation Diet, and Caloric Restriction

Intermittent fasting, as previously mentioned is not technically a form of starvation at all. Almost all mammals who walk the earth today are highly specialized organisms whose metabolic systems are highly adapted to periods of IF.

Despite the common warnings in health and exercise journals that the key to proper health and exercise is constant and regular eating, a vast body of research shows this to be completely erroneous.

One or two 24-hour periods per week with no food intake has been shown not only to be safe, but actually beneficial for metabolism and overall health. This is not long enough for your body to enter starvation mode.

Again, intermittent fasting is not a new concept. It was not until the advent of the industrial revolution and the subsequent creation of the food industry that humans began to eat daily, calorie-rich diets.

Along with people started to view IF as a sign of poverty and ill health.

For millennia of human history, our ancestors regularly missed food for short periods and experienced nothing like the sort of metabolic diseases our society suffers from today, e.g., diabetes mellitus, obesity, chronic fatigue, etc.

Sensible Weight Loss Strategies

Healthy weight loss can only be accomplished by limiting calories in a sustainable and regular fashion. Proper care of our metabolism is key.

Crash diets tout quick and easy weight loss, but the long term effects can be devastating. Induction of starvation-mode metabolism is unhealthy and carries the risk rebound weight gain and more.

The type of alterations seen in the mitochondria in response to cycles of starvation and weight gain can be permanent and lead to cardiovascular disease, insulin-insensitivity, chronic fatigue, and inflammatory diseases.

Crash Diets Can’t Get Rid of Toxins

Some people believe going on a severe starvation diet can help in getting rid of toxins from the body. Many nutritionists find this idea alarming, despite the seemingly logical point of restricting the intake of harmful substances and food.

Sure it can prevent more toxins from entering the body but no scientific proof has been found of the fasting diet actually “cleansing” the body of these substances.

The body can already detoxify substances through the kidneys, liver, colon, and even the skin.

People going through starvation diets “cleanse” their bodies for 2-3 days but may end up eating twice more than they usually did after the period. This causes spikes in blood sugar, cholesterol, uric acid, and more.

They also experience dehydration and diarrhea from drinking laxatives on top of the calorie deficit.

Healthy Eating Diet Plan

Doctor nutritionist writing case history in the office | What You Need To Know About Fasting, Starvation Diet, and Caloric Restriction

Unlike starvation diet plans, IF does not restrict calorie intake. It focuses on readjusting the body’s functions to use the fats in the body instead of muscle loss.

IF encourages people to still eat healthy meals during the eating window. But then, consuming unhealthy, junk foods defeats the entire purpose of IF.

Regardless of any kind of diet plan, your body should consume nutrient-dense foods for the organs to work smoothly and properly. Partnered with the keto diet, IF guarantees safer long-term weight loss goals.

What is a keto diet? This type of diet plan eliminates sugar and limits carbohydrates to bring the body into a ketosis state, which uses fatty acids as energy instead of glucose.

Starvation diets may work in shedding a lot of weight in a short period of time, but you’re also depriving yourself of nutrients like protein, calcium, and vitamins. In the long run, your metabolic rate drops, causing digestion problems and chronic diseases.

Fasting for weight loss has its benefits and consequences. A starvation diet may help lose weight in a short amount of time but it can also cause your body to bounce back twice as much.

Intermittent fasting, on the other hand, acclimates the body into certain periods without causing harm to the mitochondria.

If you want to go on a diet to lose weight, make sure you understand the intricacies of each diet plan. This way, you’ll be able to reap maximum benefits without encountering health risks in the future.

In the coming months, Juvenon Health Journal will continue to explore different facets of a healthy, efficient metabolism.

Have you tried the starvation diet or intermittent fasting? Share your experience in the comments section below!

Up Next:

What You Need To Know About Fasting, Starvation Diet, and Caloric Restriction https://blog.juvenon.com/fasting-starvation-and-caloric-restriction/

Editor’s Note: This post was originally published on March 19, 2014, and has been updated for quality and relevancy.