Intermittent Fasting

Intermittent Fasting is a method of voluntary fasting, usually for a certain number of hours a day with a specific goal to reduce body weight and change body shape or to achieve certain metabolic endpoints. Although it is quite a new fad the reason why it is gaining popularity is the thinking that for primitive man, food would have been scarce and that he would have had to go without food for prolonged periods of time. So Intermittent Fasting as apposed to frequent feasting (as we do in the 21st century) may actually have been the way we humans were biologically designed to eat. And that the habit of having three square meals and innumerable snacks in between is a modern one and probably the one that is causing an explosion of lifestyle diseases starting with the obesity and then progressing onto dyslipidaemia, hypertension, diabetes, cardiovascular disease and finally cancer. Further everything we do culturally and socially involves food and this therefore makes it very difficult for most of us to even consider Intermittent Fasting as a choice for better health (would you call it a party if food wasnt supplied by the host??). For a long time, I was a sceptic of intermittent fasting methods but the more I read and saw, the more I tended to believe in its benefits. Recently an uncle who at 85 yrs is a retired doctor and a national level athlete spoke about following a 18:6 IF regimen and triggered my interest in researching the medical evidence for IF. So here are some extracts and excerpts from what I have read.

What are the popular I.F regimens?

Daily time restricted feeding i.e., fasting for >12 hrs a day, alternate day fasting and 5:2 intermittent fasting (starving 2 days each week and eating normally on other days) are the. 3 most popular methods of IF.

So what happens in the body when you start Intermittent Fasting?

During I.F the energy producing mechanisms essentially change from being glucose based to one dependant on ketone bodies. All food that is digested is stored in the the liver as glycogen. Glycogen is essentially a long string of glucose molecules bound togetherin chains. In times of need, individual molecules of glucose are released for the use of the body. When one does intermitted fasting, the glycogen stores are already depleted and so the body starts to dissolve the fat stores by releasing triglycerides which are converted to Ketone bodies in the liver. Ketone bodies are a denser source of energy for a variety of cells especially for the brain. Ketone body production starts to rise only after 8-10 hours of fasting suggesting a minimum of 12 hrs of fasting for any real benefit from I.F. Switching to Ketone bodies to provide energy results in reduced respiratory exchange ratio i.e., reduce usage of O2 and therefore reduced production of Carbondioxide, representing a more efficient process for production and usage of energy.

While it is not clear if the benefits of IF are due to simply weight loss alone or because of metabolic switching, the many benefits of IF include improved glucose regulation, improved blood pressure and heart rate control, improved endurance training and loss of abdominal fat and body weight. Other benefits include increased life span, improved memory, balance and coordination (in Alzheimers and Parkinson syndrome), reduced blood pressure, lipids and reduced occurence of spontaneous cancers and slowed growth of certain other cancers.

So what are the cellular changes brought about by I.F?

Reduced Oxygen usage in ketone body metabolism results in reduced production of corrosive free radicals and therefore reduced oxident mediated cellular damage. Ketone bodies have an effect in suppressing inflammation and reducing cellular stress and improving specific tissue growth and plasticity. Ketone bodies are potent signaling molecules and regulate the expression of various proteins and molecules that are known to influence health and aging. (PGC-1gamma, Fibroblast factor 21, NAD, sirtuins, PARP1 and ADP ribosyl cyclase).

IF and Obesity and Diabetes:

Compared to women who only reduced their food intake by 25%,women who followed a 5:2 IF program had a greater increase in insulin sensitivity and reduction in waist circumference although both groups showed equal overall weight loss. In young men who fast fo 16hrs a day and hit the gym for weight training have fat loss along with preserved muscle mass. IF is as effective as standard diets for weight loss. In rat models, IF is associated with greater muscular endurance.

Weight loss with IF is associated with improved insulin sensitivity and improved diabetic retinopathy. Markers of inflammation have also been noted to reduce especially in patients with Rheumatoid arthritis.

IF and Cardiovascular disease:

IF brings about reductions in Blood pressure, reduces heart rate and increases heart rate variability. Lipid profile also improves with reductions in the levels of LDL, Triglyceride and increase in HDL values. Improved indicators of cardiac health were noted as early as 2-4 weeks of starting IF.

IF and neurological disease:

In experimental animal models of IF hadve shown delayed onset of Alzheimer’s disease and Parkinson’s disease. IF increased neuronal stress resistence by bolstering mitochondrial function and DNA repair. GABAminergic transmission is enhanced and this can prevent seizures activity. IF reduces autoimmune demyelination in mouse models of multiple sclerosis and after traumatic and ischaemic spinal cord injury and leads to improved functional outcomes. In humans, IF has shown to improve memory (verbal spatial and working memory).

IF and Cancer:

IF reduces the occurence of spontaneous cancers and also my other types of induced cancers in mouse models. Calorie restriction with IF impairs energy metabolism of cancer cells, reducing their growth and rendering them suseptible to chemotherapy. Several studies with Glioblastoma suggest that intermittent fasting can suppress tumour growth and extent survival.

Suggested regimens for daily time restricted feeding

Month 1 10 hr feeding period 5 days a week

Month 2 8 hr feeding period 5 days a week

Month 3 6 hr feedine period 5 days a week

Month 4 6 hr feeding peiiod 7 days a week

Suggested regimen for 5:2 Intermittent Fasting

Month 1 1000Kcal 1 day a week

Month 2 1000 Kcal 2 days a week

Month 3 750 Kcals 2 days a week

Month 4 500 Kcals 2 days a week

Celebrities who have used Intermittent fasting to reduce their weight.


As a doctor I see many people who want to reduce their body weight for a variety of reasons including to improve their health, body image or personality. Unfortunately only a few actually achieve their weight goals and succeed in keeping their weight down for prolonged periods. Most have some early gains and then either stop losing weight further or put the lost weight back on despite everything that “they think” they may be doing. They then become frustrated or depressed and sometime totally give up the “battle of the bulge”! Many take solace in food and put on more weight on the rebound. I will put down in this article what I have seen successful weight losers do to achieve their target.

The first part includes some points for you to consider. The second part contains some strategies for weight loss.

Things to consider:

1. As someone said, “failing to plan is planning to fail”! You have got to have a written plan of action to achieve your body weight targets.

a. Set your body weight target (what do you want your body weight to be)- e.g., 10kg less-

   write it down!

b. When do you want to achieve this weight? E.g., in one year’s time 1st March 2021.

c. Put down interim goals – quarterly goals viz 2.5 kg weight loss every 3 months which would be 1 Kg weight loss every month.

Someone also said “the difference between working with a goal and without a goal is…………………….…result”. Consult your doctor and do the necessary tests to certify your cardiac fitness to begin your weight loss programme.

d. You have got to put up an exercise schedule and diet chart. You could consult a dietician to help you plan your meals and the low calorie in-between meal snacks too.

2. “Whatever gets measured, improves” {someone said 🙂 } . Buy a good digital weighing scale and check your weight every Sunday, early in the morning soon after waking, after evacuating your bladder and before you take anything by mouth. You want to definitely do this as half a litre of water taken, will definitely increase your weight by half a kilo! Record each measurement in a book against the date of measurement.

3. You have got to accept that what you have done in the past to reduce weight, just wasn’t enough. You have go to do something quite drastic and consistently to achieve your goals. You would need to cut the calories that you eat as well as increase the amount of exercise that you do (volume of exercise as well as Intensity). This also needs to be documented everyday. You can sum it all up at the end of the week to see how well you have stuck to your plan.

4. If you don’t achieve your weekly goal, be hard on yourself the following week and either go on a stricter/ lesser diet or exercise more or do more of both! Be brutally honest with yourself. Don’t accept excuses for your inability to reach your goal or to follow your own weight loss plan. Achieving these smaller weekly goals will ensure that the larger monthly goals, quarterly goals, half yearly goals and the final goal are all achieved (as planned).

5. Changing your thinking is a given. But you absolutely have to change your lifestyle and habits to achieve your weight loss goals.

a. Separate food from the good times. Don’t attend parties where food is the main draw.

Have a green tea party. Avoid junk food when having alcohol. Don’t sit in from of the TV with junk food to munch on.

b. Eat out less often and when you do, fill yourself up with low calorie salads before going onto the main course. Share your main course with someone else. Avoid eating deserts completely.

c. Don’t keep high calorie snacks at home and if you do take them, buy them one at a time (not an entire box full and a small portion too). A good example is chocolate.

d. Avoid all kinds of bakery foods (bagels/ white breads/ cakes/ pies etc)

e. Take twice as long to eat. Chew each mouthful 30 times before swallowing.

f. Have more of the food that you don’t like and completely avoid what you do! This way you would get all the nutrition without the craving to eat more!

6. Plan your snack and in-between meal foods. Salads, green tea, low calorie fizzy drinks and water will definitely reduce your hunger and help you get by till the next meal. A high protein shake is a good way to reduce your hunger without increasing the risk of weight gain. However you should make sure that you are using a pure protein powder drink rather than a balanced protein supplement drink (which would have less protein and is used as a post-exercise re-fueller).  

7. All habits take 3 weeks to form and 3 months to become permanent. Grit your teeth and stay strong for this period especially during the first 3 weeks. It should become easier after this.

8. Take an Antacid especially if you develop acidity when eating smaller quantities of food. Remember the food you enjoy is the one that is particularly harmful to your goals.

9. When all else fails, don’t hesitate too much to go under the knife. Bariatric surgery does wonders for many.

Strategies to lose weight

What is most important is to develop a daily calorie deficit. Food intake in terms of calories must be less than calories expended by exercise. If you can reduce your daily food intake by 300-400 KCals and increase the calories spent by another 300-400 KCals you could achieve a 700-800 Kcal deficit which over the week would amount to 3500-5000 Kcals and a weight loss of 1/2 a Kilo of weight per week and a 2 Kg weight loss per month! (if consistently done)

Exercise daily but vary the intensity and duration of exercise. Training is to be done in cycles of increasing volume and intensity of exercise. This not only keep the challenge up but makes exercising more interesting. Make exercise a part of your daily living – walk up the stairs, walk to the neighbourhood shop, take the train or the bus instead of using your car, cycle to work etc. Listen to your body and don’t push yourself when you are tired. Ensure that you get 7-9 hrs of sleep a night.

Eat everything but reduce the intake of carbohydrates (alone) by 25% at each meal. Compensate for the reduced volume of food by eating a lot more of salads and less calorie dense meals and snacks.

You could consult a professional dietician and take a very low calorie diet. (600-900 Kcal/day) Again taking plenty of salads would help a lot in reducing your hunger and keeping you sane.

Try a completely different diet – Keto/Paleo/Atkins etc

Try a 24 hr fast or fast for at least for 16 hrs a day for 2 days a week. There is some evidence that this is equally effective as eating less (dieting) every day. So you would get the pleasure of eating normally on most (except 2 days) of the week.

Reduce your meals to just 2 a day. Skipping dinner would probably be the best. The food that is taken at night gives calories that just stick to the body. Your metabolism is the slowest when you sleep and therefore the food eaten is  not consumed as it might be in the morning. Skipping dinner will therefore help in weight loss.

Essential supplements that you may need when you go on a weight loss diet are the following:

– Multivitamin mineral tablet

– B complex tablet

– Fish oil (omega 3) capsule

So to summarise

Write down your goals, targets and timelines.

Start your diet and stick to the plan.

Do your exercise 6 days a week.

Check and record your weight every week at the same time.

Reduce your food intake and increase your exercise volume if you haven’t reached your weekly target. Continue the same if you are satisfied with your weekly weight loss.

Have someone you should be answerable to – a weight loss coach!

Best wishes for your success!

Here is a interesting YouTube link

Hunger and how to kill it!


I suddenly realised that it would be good to write about hunger and how to control it when I started writing about diets in general and Diabetic diet in particular. It is quite obvious that if someone can’t control his hunger, he won’t be able to control what he eats and therefore won’t be able to achieve his health goals. So quite often when you repeatedly fail in your attempts at controlling hunger, you just give up. So let us talk about what is hunger, why it happens and how it can be controlled.


Hunger is a sensation that represents the need to eat food. It is that uncomfortable feeling in the pit of your tummy that tells you that you need to fill your tummy with food. Satiety on the other hand is the absence of hunger and a feeling of fullness. Appetite is the desire to eat food.


It is said that hunger is essential for survival, development and evolution. If there was no hunger (as it might be in heaven), there would be no sadness, no misery, no greed, no ambition, no development, no competition, no lifestyle disease, no change, no migration, no violence etc etc.


So while hunger is essential for our own survival, like every other urge of the body and mind, it should be controlled for us to live happy healthy and fuller lives. Hunger management is most important for those trying to lose weight or for those living with diabetes. Let us look briefly at the hunger mechanisms and at things that one can do to control it.



There are many different mechanisms by which we become aware of hunger.  You can look at them as Gastric, Intestinal/hormonal, Neurological/ psychological and others.



Empty stomach increase hunger.

Increased Gastric acidity


High Glycaemic index foods

 Low protein and fat in diet

 Low ruffage/Fibre diet

 Fast foods or anything that you  eat out of a package or parcel foods.


Poor sleep can increase hunger (Ghrelin levels increase by 28% and Leptin reduce by upto 18%)

 Life stress can increase  hunger

 Although exercise can increase hunger in the long term, exercising when hungry can make you forget your hunger.

 Having an unsatisfactory meal can also trigger increased hunger.

 Having too much alcohol the previous night and dehydration can increase hunger.


Insulin peaks after a high carb diet or sugary meal (especially in diabetics), cholecytokinin, Neuropeptide Y levels and increases Hunger

 Low blood sugars even in non-diabetics can increase hunger.

 Glucagon and Adrenaline reduce Hunger (during stress anger rage etc)

 Leptins produced in fat cells reduce hunger. Leptin secretion increases with increased food intake and reduces with fasting or starvation.

 Ghrelin produced by the stomach stimulates hunger.

 Hyperthyroidism can increase your hunger.


Hypothalamus area of the brain controls hunger and strokes affecting the hypothalamus can cause uncontrolled hunger or reduce appetite depending on the part of the hypothalamus affected.

 Dopamine induces satiety and reduces appetite

 Serotonin also reduces appetite by acting via neuropeptide Y and Agouti related peptide (AgRP) and Pro-opiomelanocortin (POMC)



 Thinking about food or smelling food or partying can increase hunger. Food is very closely associated with fun and friends.


Tricyclic antidepressants , steroids and antipsychotics increase hunger.


 Suggested ways to combat Hunger


Fill your tummy with a large quantity of water when hungry.

 Eat a healthy snack one hour before your meals.

 Split your meals in 2 and have them 20-30 mins apart.

 Avoid a high Glycaemic index meal. Avoid large deserts (cakes/ ice creams etc)

 Incorporate more proteins/fats into your meal.

 Chewing your meal well (15-30 chews of each mouthful) can reduce your hunger and food intake.

 A meaty meal can suppress your hunger more effectively.

 Plan your meal in advance. Take a healthy in-between meal snack.

 Take in a large bowl of high fibre vegetables with every meal. Veggies slow down gastric emptying and therefore keep the stomach full for a longer period thereby suppressing hunger.

 Avoid ultra-processed foods – the feel good/tasty/palatable foods!

Avoid high salt and sugar contains foods. This would include virtually all fast and  processed foods. (nearly everything that is not cooked at home on a regular basis)


Contact your doctor for any medication that could help you reduce your appetite.  Metformin/ Liraglutide/ Setmelanotide can be useful in helping you manage your hunger.


 The following natural foods are believed to be able to suppress Hunger!

 Food additives


 Cayenne pepper


 Hot sauce



 Dark chocolate

 Flax seed


Oat meal


 Veg soup

 Whole Salads

 Greek yoghurt

 Vegetable juice





 Green tea

 Skimmed milk

Fruits and Vegetables

Avocados in moderate quantities

 Apples – rich in pectin and fibre

 Green leafy vegetables


Whey Protein


 I hope that the information given above is of some use to you. My intention is not to write a comprehensive all including essay on hunger but just to give you enough information to stimulate your curiosity to begin your own research into your hunger, to experiment and see what would work for you and to change your eating habits to achieve your best health.


A hundred years ago, the concept of food storage wasn’t existent in most parts of the world. People hunted and gathered food that they cooked immediately and ate (unless it was rice that was harvested and stored for a while). In today’s world, most of us in the city do not face food shortages as we have the means to store food for long periods. Our food culture has also changed so much that we have also started eating very high salt/sugar containing calorie dense foods that are very addictive. Having easy access to these addictive foods promotes this dependance and we end up eating more than we want, to put on more weight than we need and then suffer more from “lifestyle diseases” than we should.