Overweight and Obesity
Overweight and obesity are defined as abnormal or excessive fat accumulation that presents a risk to health. A body mass index (BMI) over 25 is considered overweight and over 30 as obese.
Obesity has grown to epidemic proportions, with over 4 million people dying worldwide each year as a result of obesity.1 India now is the third most obese country in the world following US and China.2
Overall, about 13% of the world’s adult population (11% of men and 15% of women) is obese. The worldwide prevalence of obesity nearly tripled between 1975 and 2016. More than 135 million individuals are affected by obesity in India.
According to an Indian Council of Medical Research (ICMR) study, prevalence rate of obesity varies from 16.9%–36.3% respectively across India. The prevalence of obesity rises from 8% to 38% in rural and 13% to 50% in urban areas.
The prevalence of overweight and obesity among children and adolescents aged 5-19 has risen from just 4% in 1975 to just over 18% in 2016
Diagnostic criteria of obesity
In a simple term if an individual is 20% more than his ideal weight, he is suffering from obesity.
1. Body Mass Index (BMI): BMI is a person’s weight in kilograms divided by the square of height in meters.
BMI is a standardized index used to define obesity and to sub categorize into: underweight, healthy weight, overweight, and obesity
2. Waist Circumference (WC) :Waist circumference is an easiest tool to measure abdominal obesity. Abdominal obesity is associated with increased risk of diabetes, cardiovascular diseases and strokes. Obesity is defined as:
WC>102 cm/ 40.15 inches (men)
WC >88cm/ 34.64 inches (women).
3. Waist Hip Ratio: Waist hip ratio (WHR) is calculated by dividing WC by the
maximum hip circumference.WHR shows a graded and a significant association, stronger than that of BMI, with risk of myocardial infarction
WHR= >0.95 (men)
WHR= >0.80 women
Fat Percentage: Measurement of body fat percentage is a direct indicator of obesity. It can be measured through bioelectrical impedance analysis (BIA) or DEXA scan. Obesity is defines as:
Fat Percentage= >25 % in men
Fat Percentage= >33% in women
Consequences of Obesity
As society moves from times of scarcity to times of plenty and excess, obesity is emerging as the most common cause of death both in the developed as well in the developing world. Obesity is responsible for increasing morbidity affecting almost all systems of the body. Diabetes, Heart disease, Hypertension, stroke, Chronic Kidney Disease, Cancers(e.g. colon, Pancreas, Esophagus and liver)are all among the life threatening consequences of obesity. Non Alcoholic fatty liver disease, osteoarthritis, sleep disorders are the other debilitating conditions associated with obesity. GERD ,Sexual dysfunction and reproductive problems, sleep apnea are some of the other obesity related conditions.
Obesity is associated with poor public perception. Social bias and rejection which in turn leads to poorer performance, anxiety, low self esteem and depression and other psychological changes and even psychiatric issues
Pathogenesis of obesity
(Pathogenesis of obesity)
The pathogenesis of obesity is complex. It is not a mere derivative of food intake & energy expenditure but seems to be a result of impaired brain signals & hormone imbalance leading to pathological over eating and decreased physical activity.
Over the years, many hypotheses have evolved to explain why some people become fat and others remain lean despite eating similar types and amounts of food, and why it is so difficult for reduced-obese persons to maintain weight loss. No single theory can completely explain all manifestations of obesity or apply consistently to all persons. Some of the pathogenic mechanisms of obesity are listed below:
· Obesogenic environment with increasing affluence, money, food abundance, too many incentives to be sedentary and too little need to be physically active is the major reason responsible for obesity.
Genetics can play important role in how the body converts food into energy and how the body burns calorie during exercise. Single or multiple genes may be involved.
Hormone imbalance: An increase in hunger stimulating hormones like Gherlin and a decrease in hunger satisfying hormones like Leptin have been postulated as a major cause of obesity.
Sleep, Stress, and Circadian Rhythms play a major part in the pathogenesis of obesity. Shortened sleep alters the endocrine regulation of the body leading to increased appetite.
Medications like insulin, steroids, anti-depressant and some form of hormonal contraception can all lead to hormonal imbalance, increase in appetite and weight gain.
Certain medical condition like PCOS, Hypothyroidism, Cushing syndrome can also be responsible for obesity
The gut microbiota have been recently implicated in the pathogenesis of obesity. They promote diet induced obesity by a variety of mechanisms the predominant mechanism being the change in the composition of the short chain fatty acids formed as a result of carbohydrate breakdown.
MANAGEMENT OF OBESITY IN ADULTS
When energy intake exceeds energy expenditure by merely 20 kcal/day (the equivalent of 1 tsp. of sugar) a person would gain approximately 1 kg of fat per year (≈20 kg over 2 decades). Hence even a moderate control of the ingested calories would pay long term dividends in managing obesit
After diagnosis of obesity evaluation of patients during the first clinic visit should be protocol-based and comprehensive.
1. History: A detailed history should include onset and rate of weight gain, family history, dietary history, physical activity, previous attempts at weight loss, current medications and co morbidities.
2. Clinical Examination: Patient should be examined thoroughly for sequlae of obesity like pigmented skin (Acanthosis), double chin, hump on the upper back between the shoulder blades etc.
3. Biochemical Evaluation: HbA1c, lipid profile, thyroid profile, OGTT (Oral Glucose Tolerance Test), HOMA IR (Homeostatic model assessment Insulin Resistance). Are all part of the standard work up for these patients. Biochemical parameters can also help in identifying the secondary cause of obesity like PCOS, hypothyroidism, ovarian disease, cushing’s disease and identifying obesity related co- morbidity.
Patient education is the most important component of obesity management. Before starting weight management program a comprehensive patient education session is mandatory.
Goals of Treatment
Obesity is difficult to treat and most patients find it difficult to sustain the weight loss that they achieve. Hence the goals of treatment should be realistic, achievable and sustainable.
It has been found in multiple studies done for diabetes, NASH and heart disease that a weight reduction of 5-10% carries significant health benefits. Therefore the initial aim for any weight loss programme should be to achieve a weight reduction of 5%.
It is recommended that the weight loss should not occur at more than 1kg per week as rapid weight loss in the elderly or those with co morbidities can itself lead to complications.
The three pillars of any successful obesity treatment programme are 1. Behavioral therapy 2. Diet and 3. Physical activity. All three are equally important for weight loss. Physical activity alone may not achieve the desired results as a large amount of physical activity is needed to reduce significant weight ( To reduce 1 kg one needs to walk 4.3 km for 1 week). In order to sustain the gains made by the combination of diet and physical therapy one needs behavioral modification so that the same eating pattern does not set in again. If this combination fails then one has to resort to 4.pharmacotherapy, 5.endoscopic therapy or finally 6. bariatric surgery.
1. Behavior Modifications:
Identification of behavioral patterns causing obesity need to be corrected to find a lasting solution. Such patterns could include: rapid eating, binge eating, night eating, snacking, sweet or alcohol craving, comfort eating etc. The environmental trigger for eating also needs to be identified and addressed .Therefore behavior counselling includes 1. Monitoring of the quantity and type of food. 2. Monitoring of physical activity and 3. Identifying and correcting the eating disorders
2. Dietary Interventions OBJECTIVE:
The aim of any weight loss programme is to:
(A) Preserve muscle mass
(B) Lose fat
(C) Maintain adequate hydration status.
(D) Incorporate essential fatty acids
(E) Avoid micronutrient deficiency
(F) Factor in the co-morbidities in any dietary regimen
Mechanism of Weight Loss-
Carbohydrates are the simplest source of energy. After digestion, carbohydrates are broken down into glucose which is the primary source of energy in the body. If we eat more than our energy expenditure, there is an excess of glucose in the blood stream. Excess glucose is removed and first converted into glycogen and stored in the liver and muscle and once the liver and muscle stores are full, it is converted to fatty acids and is subsequently stored as fat in adipose tissue. These actions are largely mediated by the hormone insulin.
In the hypocaloric state (Individuals taking less calories than needed), initially there is a breakdown of stored glycogen to meet the energy requirement. If this is not sufficient, there is a breakdown of amino acids in muscle tissue as well as the breakdown of fat to produce glucose. The body glycogen stores are limited and usually do not last beyond 12-18 hrs. Since muscle is much more metabolically active, muscle breakdown occurs after glycogen fat utilization happens the last. The same process works in individuals undergoing vigorous physical activity.
The aim of any weight reducing diet is to reduce the amount of fat while at the same time preserving the muscle mass. Muscle breakdown is prevented only if there is sufficient carbohydrate present as a energy source and muscle regeneration occurs only if there are sufficient protein and amino acids available in the diet. Hence all weight reducing diets should have an adequate amount of carbohydrate and protein to prevent the breakdown of muscle.
How to calculate calorie intake:
Step 1: Calculate Your BMR (Basal metabolic rate)
For women, BMR = 655.1 + (9.563 x weight in kg) + (1.850 x height in cm) - (4.676 x age in years)
For men, BMR = 66.47 + (13.75 x weight in kg) + (5.003 x height in cm) - (6.755 x age in years)
Step 2: Calculate Your Calories by multiplying the BMR x the AMR (Active metabolic rate)
Sedentary (little or no exercise): AMR = BMR x 1.2
Lightly active (exercise 1–3 days/week): AMR = BMR x 1.375
Moderately active (exercise 3–5 days/week): AMR = BMR x 1.55
Active (exercise 6–7 days/week): AMR = BMR x 1.725
Very active (hard exercise 6–7 days/week): AMR = BMR x 1.9
General measures to reduce weight
1. Healthy dietary habits go a long way in preventing obesity.
a. Eat unhurriedly with each meal lasting over 20 mts
b. Do not do multitasking while eating- No TV, telephone or newspaper.
c. Chew the food well, enjoy the meal.
d. Eat at a designated area, do not eat in the bedroom.
e. Breakfast should be the heaviest meal followed by lunch and dinner the lightest.
f. Dinner should be early and never beyond 8 pm.
g. Do not eat after dinner.
h. Avoid sugary beverages like juices, colas or sherbets instead just have water.
i. Avoid comfort foods
j. Practice portion control
k. 6-8 hours of sleep in necessary to reduce hormonal imbalance and excessive eating.
l. Avoid perpetual anxiety as it leads to hormonal imbalance, overeating and obesity.
m. Instead of taking 3 heavy meals divide it into 6 meals (3 moderate meal along with 3 light snacks). This reduces the craving for food.
n. Never feast and fast. Skipping meal can induces water loss, muscle loss and reduce the metabolic rate which eventually causes weight gain.
Principles of dietary interventions
1. The basic dietary principal of weight loss is to restrict the total calories while at the same time preventing muscle wasting. Thus a diet should be hypocaloric with sufficient amount of protein.
2. A review of the current total intake of the patient needs to be made based on his eating habits and the present amount of calories calculated.
3. The desired calories for weight reduction calculated and a new diet designed around it. The diet should have minimum deviation from the type of foods eaten otherwise it becomes unsustainable.
4. To prevent the breakdown of muscle protein, the diet should have a sufficient amount of protein. Incorporate good sources of proteins like soyabean, eggs, chicken and fish. Minimum protein requirement for an individual is 1g/kg ideal body weight. This can vary in specific situations like patients with renal failure need less proteins while those doing high resistance exercise need more proteins.
5. The remaining calories should be divided between fats which should constitute 35% of the total calories and carbohydrates 65%.
6. Dietary fiber should be there in abundance as it reduces the absorption of food and increases satiety.
7. There should be adequate hydration and at least 2 liters of water is recommended, Water acts as a catalyst for accelerating the several processes in the body & nutrient movement
8. There should be more complex carbohydrates like vegetables, salad, whole grains & whole pulses. Complex carbohydrates increase the gastric emptying time & provide satiety for longer period of time.
9. Include more vegetables to get adequate fiber, vitamin, minerals and antioxidants especially seasonal vegetables& colored vegetables.
10. Follow right cooking techniques in order to avoid the loss of nutrients, for example instead of fine chopping cut into large pieces, avoid washing after cutting or chopping, do not overcook & use less oil while cooking. Include more salads & sautéed vegetables.
11. Refined carbohydrates and sugars lead to a sudden rise in glucose levels, this sugar is stored by the body as glycogen and subsequently as fat. Thus contrary to the perception that all carbohydrates need to avoided, it is the refined carbohydrates like maida and sugar which need to be avoided and not the complex carbohydrates.
12. Fat is essential for the absorption of vitamins and cell generation in the body. Essential fatty acids are not synthesized and can only be acquired through the diet.. Fat intake should be less but healthy fats like nuts, seeds, avocado, and vegetable oils need to be there in the diet in adequate amounts. Avoid Trans fat like fried foods.
Types of diets
The basic concept of dietary intervention to reduce weight, to reduce the total number of calories consumed while maintaining muscle mass and micronutrients. This can be achieved in a number of ways:
1. The balanced low calorie diet: The total number of calories is reduced with a balanced reduction in fats as well as carbohydrates-. (The DASH diet, Mediterranean diet)
2. The low fat diet: The total fats are reduced to less than 20% of the diet. (The Ornish, Pritkin diet)
3. The low carbohydrate, high fat diet : Carbohydrates are reduced to less than 30% of the diet and the calories are derived from fat. (The Keto diet)
4. A high protein diet: The calories are derived from proteins and both fats and carbohydrates are reduced. (Zone diet, Atkins diet)
5. Intermittent fasting: The total food is to be consumed in an 8 hour period in a day or fasting for 2 days in a week.
A balanced low calorie diet
These are diets which maintain the overall ratio of Carbohydrates (60%) Proteins (30%) and fats (10%) while reducing the total calories. The principle of balanced low calorie diet is to create a calorie deficit of 500-1000 kcal/day by providing a range of food choices to achieve nutritional adequacy and compliance with slow and effective weight loss.
The balanced low calorie diet can achieve a remarkable reduction in weight, body fat, waist hip ratio, Improvement in glycemic control and lipids. Individuals taking such diets do not complain of hunger; rather, they feel there is too much to eat. Hence the diet is more sustainable than the other fad diets. The classical examples of balanced low calorie diet being the DASH (Dietary intervention to stop hypertension) and Mediterranean diets.
Mediterranean diet is based on the traditional eating pattern of Mediterranean countries where the focus is on adding more green leafy vegetables, legumes, whole grains, nuts and olive oil in the diet on a daily basis. Poultry is included once a week in moderate amounts while fish is included thrice a week, red meat and wine consumption is occasional. Dairy products are consumed in moderation. Only one-third of the diet consists of fat which includes essential fatty acids, while saturated fats not exceed 8 per cent of calorie intake. This type of diet is similar to the types of food that we consume in India.
The DASH diet was designed to prevent and treat high blood pressure. It is also an effective way to reduce weight as it is a balanced hypocaloric diet. The DASH diet consists of four to five servings of fruit, four to five servings of vegetables, and two to three servings of low-fat dairy per day. Less than 25 percent dietary intake is from fat.
The Low Fat Diet
Low-fat diets are defined as diets with 11-19 percent fat, whereas very-low-fat diets have <10 per cent fat. Low-fat diets are also usually by default high-carbohydrate diets and they are moderate in protein. Popular low fat diets are the Dean Ornish and the Pritikin diet. Low Fat Diets consist of vegetables, fruits, whole grains and beans, egg white, non-fat dairy, soya and flour. Low fat diets have been shown to result in sustained weight loss in long term studies.
Fat is essential for palatability of diets, therefore very-low-fat diets are usually less palatable. Long-term compliance can thus be a problem with these diets. Low fat diets can cause micronutrient deficiency as fats are needed for the absorption of vitamins A, E, D and K. B12, zinc, Iron, Calcium and phosphorus deficiency has also been reported.
Ketogenic Diet or Keto diet
These are diets having 55% to 60% fat with less than100 g of carbohydrate per day. Restrictions of carbohydrate to less than100g induces ketosis which causes fat mobilization. Once there is low carbohydrate state, the body is forced to metabolize fats as a source of energy this process is known as ketosis and the resulting ketones are used by the brain as an energy source.
As a result of increased fats in the diet, the appetite is suppressed; this causes weight loss and reduction of blood glucose and blood insulin levels. Long term compliance of the keto diet is low because of side effects like bad taste in mouth, constipation , diarrhea, dizziness, headache, insomnia, nausea, thirst , and tiredness, weakness, or fatigue
A high protein diet
There is no standard definition of a “high-protein diet;” however, intakes greater than 25% total energy or 1.6g/kg per day of body weight can be considered high. The most common example of high protein diet is The Zone diet (30% protein, 40% carbohydrate, and 30% fat) or the Atkins diet
High protein diets are said to have a significantly higher weight loss as well as weight maintenance than the standard normal protein diet. This is mediated by 1. Increasing diet induced thermogenesis. 2. Promoting satiety and preserving lean body mass.
Intermittent fasting is basically a lifestyle change and behavior modification. Intermittent fasting advocates consuming food within a limited time frame and fasting for the remaining time.
People on intermittent fasting do not have to restrict any food group but need to ensure that whatever they are consuming during permitted period should be nutritionally balanced. In the fasted state, they are only allowed to drink water, diluted Apple Cider Vinegar and unsweetened coffee or tea with a spoon of milk.
There are different types of Intermittent fasting like 16:8(Fasting for 16 hour and eating for 8 hour each day), 5:2(Eating for 5 days & fasting for 2 days per week).
Since intermittent fasting involves remaining hungry for long periods of time, it is difficult to sustain and needs a high degree of motivation. It is also not appropriate for individuals who are required to eat meals at regular intervals such as type 1 diabetes, pregnant and breastfeeding women, elderly, individuals with eating disorders and those in need of regular food intake to take medications.
Type of cooking oil
Fats an important macronutrient of healthy diet. The predominant mode of fat ingestion in the diet is by cooking oils. According to properties of fat sources fat are basically classified into following groups:
1. Saturated Fats (SFA)
2. Trans Fat
3. Monounsaturated Fat (MUFA)
4. Polyunsaturated Fat (PUFA)
1. Saturated Fat: Saturated fats are natural oils which are solid at room temperature. Some common examples of saturated fats are: Ghee, coconut oil, palm and palm kernel oil. These oils have been traditionally used for ages in Indian cooking. They fell out of repute about two decades ago due to the fear of increased incidence of heart disease however they are back in favour again in moderate amounts with the American Heart Association recommends aiming for a dietary pattern that achieves 5% to 6% of calories from saturated fat i.e. approx 13g of saturated fat/day.
2. Trans Fat:
Trans fats are prepared by adding hydrogen to liquid vegetable oil to make them solid. Like vanaspati, Dalda etc. Reusing of any oil for repeated frying (e.g. chips, Samosa, Puri) can also produce trans fat. Trans fats are used extensively in the food processing industry as they are inexpensive, can be used repeatedly and give a desirable texture and taste to food.
Trans Fats are harmful if consumed regularly, they cause a rise in LDL levels and lower HDL levels. Trans Fat can increase the risk of heart disease and stroke. Trans Fat is also associated with high risk of type 2 diabetes due to insulin resistance. They are associated with a number of cancers.
Trans fats can be found in many foods – including fried foods like doughnuts, and baked foods including cakes, pie crusts, biscuits, frozen pizza, cookies, crackers, and stick margarines and other spreads.
The American Heart Association recommends cutting back on foods containing partially hydrogenated vegetable oils to reduce trans fat in diet and preparing lean meats and poultry without added saturated and trans fat.
3. Mono Unsaturated Fat (MUFA): Are plant based oils that contain monounsaturated fats they are typically liquid at room temperature but start to turn solid on reduction of room temperature. E.g. Olive, Peanut, Mustard Safflower Canola oils.
4. Poly unsaturated Fat (PUFA): PUFA are also an unsaturated fats which have more free carbon bonds. They are also liquid at room temperature. The American Heart Association suggests PUFA can lower the risk of heart disease and 8-10 percent of daily calories should come from polyunsaturated fats.
PUFA are found in high concentrations in Sunflower, corn, soybean, and flaxseed oils, Walnuts, Canola oil (Has both MUFA and PUFA).
Use of multiple oils in a day to provide adequate combinations of saturated, PUFA and MUFA fats are recommended for cooking by both the American heart association and ICMR. Mustard and canola oils are among the better cooking oils due to their favorable content of essential fatty acids, low SFA, and high MUFA content along with their relative stability during cooking. Similar good cooking oil combinations can be rice bran oil and safflower oil, coconut oil and sesame oil and canola oil and flaxseed oil. All these oils improve lipids and reduce the risk of heart disease.
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