You’ve probably heard about a popular new trend: intermittent fasting. Some people try it to lose weight, while others use it to lower their risk of chronic illness and stay healthier. What is it exactly, and how does it work? This article explains the basics and offers guidance on getting started—especially if you have hypothyroidism.
What is intermittent fasting?
Intermittent fasting is an eating pattern that limits when you eat, not what you eat. You cycle between periods of eating and fasting, without strict rules about food choices. It’s better described as a schedule or routine than a diet.
Common methods:
– 16/8 (Leangains): Skip breakfast, eat during an eight-hour window, and fast for sixteen hours.
– Eat-stop-eat: Fast for 24 hours once or twice a week.
– 5:2 diet: Eat normally five days a week, and restrict calories to about 500–600 on two nonconsecutive days.
Benefits of intermittent fasting
Fasting triggers changes in the body at the cellular and molecular level. When done properly, these changes can offer several benefits:
– Improved insulin sensitivity and lower insulin levels, which helps the body use stored fat for energy.
– Increased human growth hormone (HGH), which can support fat loss and muscle maintenance.
– Enhanced cellular repair through autophagy, the process that helps clear out old cells and proteins.
Intermittent fasting for weight loss
Many people try intermittent fasting to lose weight. Along with hormone changes, fasting often leads to eating fewer calories than you burn, which creates a calorie deficit. Some studies report that intermittent fasting can raise metabolic rate by about 3% to 14% and reduce body weight by about 3% to 8% over three weeks to six months, depending on the method and consistency.
But weight loss depends on what you eat during your eating window. Overeating junk food after fasting won’t help. A balanced diet and regular exercise are still important.
Other benefits include:
– Reduced inflammation
– Lower risk of diet-related chronic diseases like diabetes and high blood pressure
– Better heart health through lower LDL (bad cholesterol), improved blood sugar, and less inflammation
– Potential brain health benefits from increased HGH and cell repair
Who should avoid intermittent fasting?
Intermittent fasting isn’t right for everyone. People with eating disorders, pregnant women, and those who are underweight should avoid it. If you have any health conditions, check with a healthcare professional first.
Intermittent fasting and the thyroid
Fasting affects hormones, including those linked to the thyroid—the gland near the base of your neck that controls metabolism and growth. This section focuses on hypothyroidism, or an underactive thyroid.
What is hypothyroidism?
Hypothyroidism happens when the thyroid doesn’t make enough hormones. It’s not usually life-threatening, but it can cause uncomfortable symptoms in adults, children, and infants.
Common symptoms:
– Fatigue
– Sensitivity to cold
– Dry skin
– Constipation
– Weight gain
– Muscle weakness
– Body aches
– Heart problems
– Depression
– Memory issues
Hypothyroidism and weight gain
People with hypothyroidism often gain weight due to:
– A slower metabolism
– Increased water retention
Treatments for hypothyroidism
The usual treatment is hormone replacement medication. Doctors also often suggest diet changes to help manage symptoms.
Intermittent fasting and hypothyroidism
Because fasting affects hormones, it can help some people with hypothyroidism—but it needs to be done carefully. For those with severe symptoms like extreme fatigue, muscle weakness, or constipation, fasting can add stress.
Tips for trying intermittent fasting with hypothyroidism:
– Start slowly. Don’t jump into a strict fasting plan—let your body adapt.
– Use sleep time as part of your fasting window to make it easier.
– Track your thyroid levels and adjust your plan if needed.
– Eat balanced meals rich in protein, vitamins, and minerals to support you through fasting periods.
– Stay hydrated. If you need something during fasting hours, drink coffee or tea without milk or sugar.
Intermittent fasting can offer many benefits and may be possible if you have hypothyroidism. If you’re interested but unsure where to begin, talk with your doctor to create a safe plan. Be patient and consistent—changes in health and fitness take time.