by Margaret S Garrett - Published 6 months ago

Calorie Deficits & Weight Loss: The Truth

Our bodies are incredibly adaptable when it comes to survival in difficult conditions. A striking example of this is adaptive thermogenesis, more commonly known as “starvation mode.”

But what exactly is “starvation mode” and how does it impact weight loss? Let's delve into the details.

Does 'Starvation Mode' Really Exist?

The concept of starvation mode is straightforward: If your body doesn't receive enough calories, it assumes you're in a state of starvation. As a result, your body may hold onto some of your weight and fat to conserve energy, making weight loss more challenging.

“Starvation mode” only kicks in when a significant calorie deficit is sustained for an extended period. While the precise duration varies based on various factors, research suggests that it can occur after approximately a week of extreme daily calorie restriction.

Signs of "Starvation Mode"

There's no way around it. Your body requires calories to function properly.

If you don’t eat enough, your body will enter "adaptive thermogenesis", the scientific term for "starvation mode." This will slow down your metabolism, causing various side effects that become more noticeable over time.

Here is a list of common "starvation mode" symptoms:

Lethargy
Constipation
Depression
Inability to concentrate
Feeling unusually cold
Reduced appetite

The specific symptoms can vary, but usually involve a general decrease in weight loss rate. Consult a doctor or nutritionist if you experience any of these side effects.

The Effects of "Starvation Mode" on Weight Loss

In "starvation mode", your metabolic rate may decrease significantly, especially if you lose weight too quickly. Metabolic rate is the number of calories you burn daily and is crucial to the balance of calorie intake and expenditure.

The exact numbers will vary depending on how fast you lose body weight, but a good rule of thumb is that adaptive thermogenesis will kick in after about one week of severe caloric restriction, which is restricting total daily energy intake to be below basal metabolic rate (BMR).

BMR is the amount of energy in calories your body needs just to do the basics—breathing, circulating blood, regulating body temperature, and repairing cells—when at rest. Think of it as the calories you’d burn if you stayed in bed all day. It’s affected by things like your age, sex, weight, height, body composition, and even genes.

And, according to registered dietitian and scientific advisory Scott Keatley, 1,200 calories is the absolute bare minimum a human body needs daily. (Aka, the lowest BMR you can have). “Even someone under 5 feet and 100 pounds needs more if they do anything beyond blink,” he says.

No, intermittent fasting is different from “starvation mode.”

First, fasting is only done for a predetermined amount of time, preventing you from going into adaptive thermogenesis.

In simple terms, fasting is a controlled, short-term caloric restriction, while starvation mode is a natural response triggered by long-term, low-calorie diets.

Intermittent fasting can be beneficial for some, providing several health benefits, such as reducing oxidative stress and boosting brain function. Conversely, starvation mode indicates damage to your body due to prolonged caloric deprivation. Remember, consult with your doctor before embarking on any new dietary regimen, including intermittent fasting, to ensure it is appropriate for you.

There is abundant anecdotal evidence that intermittent fasting has aided individuals in weight loss when combined with a healthy, whole-food diet.

The initial, and potentially most frustrating, side effect of low-calorie diets is that "starvation mode" can hinder your weight loss progress. This can quickly become a vicious cycle: you eat less because you're not losing weight, and you don't lose weight because you're not eating enough.

Over time, starvation can also lead to a decrease in your muscle mass due to the overall reduction in calories, weight, and energy. Similarly, your overall body temperature will decline.

A body in “starvation mode” for an extended period is more vulnerable to illnesses and wounds. The risk of anxiety, irritability, and depression also increases, and you may even develop feelings of guilt and shame surrounding food.

Here are some other long-term “starvation mode” side effects:

Reduced heart muscle size
Reduced blood pressure
Social withdrawal
Changes in your menstrual cycle
Impaired immune system
Weak bones

If you think you may be in starvation mode, we suggest you notify your doctor right away.

Key Principles for Successful Weight Loss

Let’s face it — losing weight can be challenging. A desperation to lose weight quickly can lead to decisions that may work in the short term but are harmful in the long run.

It is crucial to avoid aggressive weight loss methods, which often lead to yo-yo dieting. Instead, focus on adopting healthy nutritional and lifestyle choices that you can maintain long-term.

Regular exercise is a key component of weight loss. Moderate exercise can significantly contribute to weight loss while promoting overall health and well-being. Even light exercise can be beneficial.

Consider your current eating habits. Are you prone to late-night snacking or emotional eating? Identifying these patterns can help you avoid unnecessary weight gain.

Keeping a food diary is a great way to track your eating habits and identify potential issues. MyFitnessPal offers a comprehensive food diary with features to help you adjust your eating habits effectively.

Boost Your Metabolism for Healthy Weight Loss

Rapid weight loss can lead to a decrease in your metabolic rate, making your weight loss journey more challenging.

Maintaining a healthy weight loss plan that boosts your metabolism through exercise and a balanced diet is crucial. The MyFitnessPal app, with its tools like a calorie tracker and food diary, is an ideal companion for your weight loss journey.