Intermittent Fasting for weight loss

Intermittent fasting is an eating pattern that involves alternating periods of eating and fasting. It doesn’t specify what to eat, but rather when to eat.

Common types of intermittent fasting include:

• 16:8 — eating within an 8-hour window, fasting for 16 hours
  
• 5:2 — eating normally 5 days a week, restricting calories on 2 days
  
• Alternate-day fasting — fasting every other day
• OMAD (One Meal A Day) — eating all daily calories in one sitting

You might find IF unhelpful or unsustainable if:

• You experience fatigue, irritability, or headaches during fasting windows
  
• You overeat or binge when your eating window opens
  
• You feel preoccupied with food or obsess about the clock
  
• Your relationship with food feels more restricted or stressful
  
• You skip meals but end up snacking late at night
  
• You find it difficult to stick to or constantly “restart” IF.
• You may find yourself excessively thirsty if you are not adequately hydrating through the day or compensating for the fluids that you get normally from food.
• You may find your menstrual cycle is affected. This is a red flag symptom and should trigger you to stop and seek medical advice.
  
• You may notice signs of nutritional deficiencies such as hair loss of brittle nails. Again you should stop IF and seek medical advice. 

Potential Benefits

• Weight loss through calorie reduction
  
• Improved insulin sensitivity and blood sugar control
  
• Simpler meal planning
  
• Possible reduction in inflammation or cellular repair (based on early research)
  
• Increased awareness of hunger and fullness cues
• Studies in animals showing increased longevity with IF compared to other dietary changes particularly with one meal a day regimes. 

Psychological or Behavioural Drivers

• Desire for more control over food
  
• Following trends seen on social media or in peer groups
  
• A sense of “cleansing” or discipline
• Some people report increased energy levels and focus, as well as more time to do other things

While some people thrive with intermittent fasting, others experience drawbacks:

• Overeating or binging after fasting windows
• Low energy, poor concentration, or sleep disruption
• Increased cortisol (stress hormone), especially in women
• Disordered eating patterns or preoccupation with food
• Nutrient deficiencies if meals are skipped or restricted
• Cardiovascular Risks some recent studies have shown intermittent fasting and lead to increased cardiovascular risk especially in those with pre-existing heart conditions.
  

Intermittent fasting can also be risky for people with:

• A history of eating disorders
• Diabetes or blood sugar instability
• Medication schedules that require food
• High physical activity needs
• Pre-existing heart conditions

If you’re considering IF, try the following:

• Start gently: Try a 12:12 or 14:10 window before jumping into 16:8
• Focus on meal quality: Include protein, fibre, and healthy fats
• Stay hydrated: Water, herbal teas, and black coffee are usually allowed
• Break the fast gently: Avoid breaking your fast with high-sugar or ultra-processed foods

Listen to your body: If fasting leaves you exhausted or irritable, it may not be the right approach

GLP-1 weight loss medications such as Wegovy and Mounjaro can make intermittent fasting easier by reducing hunger and helping you feel satisfied between eating windows.
These treatments mimic the natural GLP-1 hormone, which slows digestion and helps control appetite. This steadier appetite response means fewer hunger spikes, cravings, or dips in energy while fasting.

For many people, GLP-1s make fasting schedules more sustainable by preventing the rebound overeating that can happen when fasts end. Combined with balanced meals during eating periods, this can improve consistency and long-term weight loss results.

You can learn more about how these GLP-1 injections work on our GLP-1 overview page.

If intermittent fasting feels stressful, unsustainable, or is negatively impacting your health or mood, you may benefit from additional guidance.

For some people, medications like GLP-1 receptor agonists can help reduce hunger, curb cravings, and support healthier eating patterns when used alongside lifestyle changes.

Medicspot offers a free 15-minute 1-2-1 call with a member of our weight loss support team. You can ask questions, discuss any concerns, and find out whether we might be able to support you.

Intermittent fasting can support weight loss for some people, but it is not suitable for everyone — especially if it leads to strong hunger, fatigue, or overeating after fasting periods. Finding the right structure for your lifestyle matters more than following strict fasting rules.

GLP-1 medications like Wegovy and Mounjaro can help by reducing appetite and stabilising blood sugar, making it easier to manage longer gaps between meals and avoid binge-style eating afterwards.

At Medicspot, our clinicians combine medical treatment and behavioural coaching to help you discover the safest, most effective approach to sustainable weight loss.

Start your free online assessment to see if GLP-1 treatment could be right for you, or use the weight loss calculator below to find out instantly if you are likely to be eligible and to see how much weight you could lose.