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.

Why do some men develop breasts and what can be done about it?

Gynaecomastia is quite a frequently encountered condition in medical practice and it refers to the presence of a palpable enlargement of the male breast. Overall the incidence of gynacomastia is increasing throughout the world across a variety of age groups for a various reasons. Some of the causes attributed are endocrine disrupting chemicals in an increasingly polluted world, obesity, anabolic steroid (androgen) abuse, widespread use of medications that cause gynaecomastia and increased prevalence of diseases that cause gynaecomastia such as testicular cancer.

Gynaecomastia is common amongst teenage boys and also in elderly people who gain weight rapidly. Gynaecomastia can occur in upto 60% of pubertal boys (usually tall or obese teenagers) under the influence of hormones and most would spontaneously subside within a year.

What are the common causes for Gynaecomastia?

Often gyanecomastia occurs when an adult puts on weight very quickly. Even in pubertal children the incidence peaks between the ages of 12-14 in response to increased and fluctuating levels of male and female hormones that are secreted by the body. Most often (70% of the times) breast size would regress within a year. So when should one seek medical help and intervention?

In a teenage boy, persistence of breast tissue above the age of 17 or a sudden increase in size with pain may necessitate a visit to the doctor’s clinic. In adults, asymmetric breast enlargement especially if located below the areola of unusal firmness/hardness with nipple changes (retraction, eczema or bleeding) should alarm the individual enough to see a doctor.

The doctor after doing a thorough examination might ask for a few tests. Screening tests may include blood tests like Liver function and kidney function tests,hormonal assays of LH, FSH, Prolactin, Free and total Testosterone, Estradiol, beta hCG and thyroid function. Other scans such as Ultrasound breast, testes, CT for chest and adrenal glands and a FNAC may also be suggested.

Treatment is usually indicated for painful large breast masses (>5cm) in size with worrying features such as nipple bleeding or discharge, eczema or enlarged lymph nodes on doctors examination.

Medical treatment with drugs such as Raloxifene, Tamoxifen and Anastrazole would help in reducing the estrogens (or theri effect) in the body. Surgery is also an option with a high success rate of complete cure (90%).

All about Vomiting – ad nauseam!

Vomiting is a process by which the body expels substances that may irritate the stomach and the intestines. This explanation is a very simplistic and our reality is that we still aren’t very sure of all the reasons and mechanisms of vomiting from the many causes.

There are many causes for vomiting. They may be classified as follows:

Gastrointestinal reasons-

Intestinal obstruction – tumours, adhesions, hernias etc

Reduced/Abnormal motility – Diabetic gastroparesis

Infection – acute peritonitis, appendicitis, gastroenteritis (bacterial and viral), food poisoning etc.

Gastric irritants -alcohol, pain killer intake, antibiotics etc

Others – pancreatitis, hepatitis, kidney stone disease, heart attacks etc

Vestibular (related to the inner ear)

Acute viral labrynthitis

Travel sickness

Meniere’s syndrome

Neurologic disease

Infections -meningitis and encephalitis

Increased pressure- tumours, strokes, intra-cranial bleeding


Psychiatric illnesses


Drugs and toxins

Chemotherapy medications

Opioid drugs


Systemic diseases

Diabetic ketoacidosis

Uraemia (kidney failure)

Adrenal insufficiency

Parathyroid disease


Mechanics of Vomiting

The process starts with increased salivation and nausea (the uncomfortable feeling of vomiting). The stomach starts contracting upwards (reverse peristalsis), the wind pipe is shut by the epiglottis reducing the chances of the vomited food from entering the lungs, the tummy muscle contract forcefully, the chest is held fixed in mid inspiration, the increased intra-abdominal pressure ejects the stomach’s contents out through the mouth and the nose.

Neural control of Vomiting

The neural pathways that bring about vomiting all lie within the brainstem. The brainstem consists of 3 areas, the midbrain, the pons and the medulla. Behind the brain stem is the cerebellum (the little brain) and above the brainstem is the Cerebrum. Between the cerebral hemispheres and the brain stem is the amygdala (which controls emotions).

There are 4 pathways to causing vomiting.

1. The stimulus from the throat (via the Glossopharyngeal Nerve) and the stimuli from the stomach and other abdominal organs (via the Vagus nerve) are carried to the Nucleus Tractus solitaries (NTS) which can not only set off the vomiting reflex but also acts by stimulating the brainstem vomiting centre. This pathway works via the serotonin (5HT3) pathway.

2. Stimuli from the inner ear and the vestibular system directly activates the Brainstem vomiting centre and brings about its effect. Histamine and muscarinic/cholinergic stimulation mediate this pathway.

3. The higher brain centres such as the Amygdala (emotion) and other centres that perceive stimuli such as pain and bad smells stimulate the brainstem vomiting centre directly to cause vomiting.

4. There exists a Blood brain barrier which protects the brain from toxins in the blood. The Chemo Receptor trigger zone is one such area that lies outside the blood brain barrier. Drugs such as opiates and chemotherapy medicines work on this area, to stimulate both the NTS and the brainstem vomiting centre to induce vomiting. These stimuli work through serotonin, NK1 and dopamine pathways.

Why should vomiting be treated promptly?

Repeated vomiting can cause dehydration, loss of stomach acid (and therefore alkalosis), loss of sodium and hyponatraemia, aspiration (when what is vomited enters the lungs) and pneumonia, rupture of the lower end of the gullet/esophagus and blood vomiting (Mallory -Weiss tears) etc.

How is vomiting treated?

Knowing which pathway is involved will suggest the best medicines to stop vomiting.

Stimuli from the pharynx (throat) stomach and other abdominal contents work through serotonin. Therefore serotonin antagonists such as Ondansetrol (Emeset), Granisetron, Dolosetron and Palonosetron will help.

Stimuli from the ear (due to vertigo, motion sickness) or from the cerebellum (due to reduced blood flow) will cause vomiting mediated via histamine receptors. This vomiting would respond well to medicines that have an antihistamine function such as Meclizine, Dimenhydrinate etc.

Stimuli from chemotherapy which stimulates the Chemoreceptor trigger zone via the Neurokinin (NK-1) receptors would respond to treatment with NK antagonists such as Aprepitant, Fosaprepitant, Rolapitant and Netupitant.

Second line antiemetics are:

1. Steroids – Dexamethasone works in ways that aren’t clear.It is definitely useful as a powerful anti-vomitng especially a second line and for vomiting after surgery.

2. Dopamine antagonists such as Prochlorperazine (Avomine) and Promethazine (Phenergan), Chlorpromazine, Haloperidol and Olanzapine (with additional serotonin blocking effects)

3. Cannabinoids also work by unknown mechanisms.

4. A combination of vitamin B6 and Doxylamine (Doxinate 24) is used for vomiting of Pregnancy.

So after reading this article and if you should have severe vomiting, you will be able to ask your doctor for better medicines for yourself!