10 Negative Effects of Prolonged Under Eating

Approximately a month ago, I conducted a consultation with a client who had been in a prolonged calorie deficit for over six months under the guidance of her previous coach.

This situation prompted several important considerations.

In any consultation, it is essential to thoroughly understand the client's previous history. This approach is not intended to critique the previous coach but to gain insight into the client's prior experiences. Such an understanding is crucial for establishing a well-informed starting point for effective and personalized guidance.

This experience inspired me to write this blog post. My goal is to raise awareness among individuals who may be chronically undereating and inadvertently causing harm to their health.

By sharing this information, I hope to help others avoid similar pitfalls and make more informed choices regarding their nutritional strategies.

Detailed Explanation of Negative Effects of Prolonged Calorie Deficit

Here’s an in-depth look at the potential negative effects:

1.     Decreased Bone Density

Why It Happens: Calorie restriction often results in lower intake of key nutrients essential for bone health, such as calcium, vitamin D, and protein. Inadequate energy intake also impairs bone remodeling processes, where old bone tissue is replaced with new. I recently learned this when I had my Vitamin D levels checked.  Reduced calorie intake can lead to a decrease in bone mineral density, making bones more fragile and increasing the risk of fractures.

2. Impaired Cognitive Function

Why It Happens: The brain relies on a steady supply of glucose and essential nutrients to function optimally. Prolonged calorie restriction can deprive the brain of these necessary resources, leading to decreased cognitive function, poor concentration, and mood swings. The brain’s energy needs are high, and inadequate intake can impair mental clarity and overall cognitive health.

3. Compromised Immune Function

Why It Happens: A prolonged calorie deficit can lead to insufficient intake of vitamins and minerals critical for immune function, such as vitamins A, C, D, and zinc. This deficiency impairs the production and function of immune cells, reducing the body’s ability to fight infections and illnesses.

4. Digestive Issues

Why It Happens: Chronic calorie restriction can lead to reduced fiber intake and insufficient energy for normal digestive processes. This can cause constipation, bloating, or other issues. The digestive system requires adequate fuel and nutrients to maintain healthy function.

5. Fatigue and Low Energy

Why It Happens: Inadequate caloric intake reduces the body’s energy reserves, leading to chronic fatigue and low energy levels. The body struggles to perform daily activities and exercise efficiently when it’s not receiving enough fuel.

7. Hormonal Disruptions

Why It Happens: Prolonged calorie restriction can affect hormone production and regulation, including hormones like leptin (hunger regulation) and thyroid hormones (metabolism). Disrupted hormonal balance can lead to increased fat storage, reduced metabolic rate, and other health issues.

8. Reduced Libido and Reproductive Health Issues

Why It Happens: For women, severe calorie restriction can lead to irregular menstrual cycles or a complete absence of menstruation), which impacts fertility. For men, it can lower testosterone levels, affecting libido and sexual health.

10. Increased Risk of Eating Disorders

Why It Happens: Prolonged calorie deficits can lead to an unhealthy preoccupation with food and weight, increasing the risk of developing eating disorders. The psychological stress of constant restriction can contribute to disordered eating behaviors.

Recommendations for Managing Calorie Deficits

How Long to Be in a Calorie Deficit:

• Aim for a duration of 6-12 weeks for a calorie deficit. This timeframe allows for effective weight loss while minimizing negative health effects. Extended deficits beyond this period can lead to adverse health outcomes.

  
  

How to Exit the Deficit:

• Gradually increase caloric intake to maintenance levels over a period of several weeks. This gradual approach helps prevent rapid weight regain and allows your metabolism to adjust.

• Focus on balanced, nutrient-dense foods to support overall health during this transition period.

  
  

How Long to Be at Maintenance:

• After exiting a deficit, spend an equal or longer period at maintenance to stabilize weight, support metabolic health, and restore any nutrient deficiencies. A general guideline is to maintain at maintenance levels for 1.5-2 times the duration of the deficit period.

  
  

Why This Approach Works:

• Gradual transitions help maintain metabolic stability, support overall health, and prevent negative effects associated with prolonged calorie restriction. Spending time at maintenance ensures that your body recovers and stabilizes before potentially entering another deficit phase.

This approach has worked for me and my clients and works for tons of other nutrition coaches I personally know. Yearlong calorie deficits can do more harm than good and odds are you have experienced all 10 or some of these negative effects of prolonged under eating.