Therapeutic Fasting: Giving the Body a Rest

Exploring how fasting can help the body rest, repair, and reset

When animals are unwell, their natural instinct is often to stop eating. This observation has inspired centuries of interest in fasting as a way for humans to support recovery and renewal. In his book Fasting and Eating for Health (1995), Dr. Joel Fuhrman explored how structured fasting can help the body redirect energy from digestion toward repair and healing.

Today, research continues to examine fasting, from traditional juice fasts to modern approaches like intermittent fasting, as a tool for metabolic health and resilience.

What Happens During a Fast

Digestion requires significant energy. When we pause from eating, the body can shift focus to other processes:

• Cellular repair — fasting activates autophagy, a process where cells recycle damaged components.

• Metabolic reset — insulin levels fall, encouraging the body to use stored fat for energy.

• Reduced inflammation — some studies suggest fasting may lower inflammatory markers.

• Gut rest — the digestive tract gets a temporary break from constant processing.

Within 12–18 hours of fasting, the body begins using fat reserves for fuel, which may release stored by-products of metabolism. This can sometimes cause short-term symptoms such as fatigue, irritability, or mild headaches, often referred to as “detox” effects.

Types of Therapeutic Fasts

There are many approaches to fasting, ranging from very strict to more supportive:

• Water fasts — consuming only water; these are the most restrictive and should only be done under professional supervision.

• Juice or broth fasts — vegetable juices or mineral-rich broths provide some nutrients while still resting digestion.

• Intermittent fasting — time-restricted eating (e.g. 16:8) has become popular for its metabolic benefits and is more sustainable for many people.

Who Should Not Fast

Fasting is not appropriate for everyone. It should be avoided or carefully supervised in:

• Children and teenagers (still developing).

• Pregnant or breastfeeding women.

• People with serious health conditions, frailty, or on prescription medications.

• Anyone with a history of disordered eating.

If in doubt, always seek professional guidance before beginning a fast.

How to Fast Safely

• Start small — beginners might try intermittent fasting or a one-day broth fast.

• Stay hydrated — water, herbal teas, and diluted vegetable broths are best.

• Listen to your body — rest more than usual during a fast.

• Break the fast gently — start with lightly steamed vegetables or simple whole foods; avoid heavy, fried, or processed meals.

• Support with nutrient-rich foods afterward — leafy greens, legumes, fresh fruits, nuts, and seeds help sustain the benefits.

In Summary

Therapeutic fasting offers the body a chance to rest, repair, and reset. Whether through traditional approaches or modern intermittent fasting, many people find benefits in energy, digestion, and resilience. But fasting isn’t a one-size-fits-all solution — it requires care, self-awareness, and sometimes professional supervision.

If you’re interested in exploring fasting, Fasting and Eating for Health by Joel Fuhrman, MD, is a valuable resource. At Health Natural, we can help guide you in deciding whether fasting is right for you, and how to do it safely.

This post is for general educational purposes and does not replace medical advice. Please consult a healthcare professional before beginning any fasting programme, especially if you have underlying health conditions or take medication.