obesity medicine The principle characteristic of obesity medicine obesity medicine is excess adipose tissue. Currently, body mas index (BMI) is an accepted and widely used measure for obesity.
BMI= weight (kg)/Height (m2)
According to World Health obesity medicine Organization (WHO) BMI classification;
BMI (kg/m2) Thinness (stage) Reference Overweight Obesity (class)
30 <30 III
25 <25 ≥25
Above table shows obesity classes and thinness stages based on BMI distribution. BMI lower than 18.5 is considered as a stage thinness while BMI ≥30 is considered as obesity.
Limitations of BMI
There are certain limitations of BMI as a measure of obesity. The body weight parameter does not tell us the percentage obesity medicine of body fat mass and lean mass. The other limitation is the lack of information regarding body fat distribution. Fat distribution in the body could be around the trunk and upper body called the android. Android fat distribution is seen as more common in males. Body fat distribution is not in the center but rather on the bottom, hips, and thighs making a pear shape called a gynoid. Gynoid fat distribution is more common in females. Android fat distribution contributes to obesity-related clinical complications. Finally, regarding ethnic differences, at any given BMI Asian females have higher body fat by 5% compared to Caucasians.
Clinical complications of obesity
Medical complications associated with obesity are:
Obstructive sleep apnea
Nonalcoholic fatty liver disease
Gall bladder disease
Polycystic ovarian syndrome
Idiopathic intracranial hypertension
Coronary heart disease
Cardiac heart failure
Breast, colon, pancreases, uterus, cervix, esophagus, kidney, prostate
Benefits of 10% weight loss
A total of 10% weight loss will beneficially improve the following conditions affected by obesity:
Neural tube defects
Cancers of breasts, esophagus, stomach, colon, endometrium and kidney
Coronary artery disease
Carpal tunnel syndrome
Chronic venous insufficiency
Deep vein thrombosis (DVT)
Diabetes mellitus type II
Gall bladder disease
Impaired respiratory function
Infection following wounds
Low back pain
Urinary stress incontinence
Obesity and mortality
Obesity is related to mortality. A prospective study conducted suggested a high mortality rate in individuals with a BMI of 30 and above.
The lowest mortality rates are for those with BMI of 20-22.
Mortality begins to increase modestly with a BMI >25.
With a BMI of ≥30, mortality of all causes increased by 50-100%
What are the risks of disease development with BMI increase
Obesity and diabetes type II
Diabetes mellitus (DM) is a obesity medicine metabolic disorder that can alter the metabolism of carbohydrates, fat, and proteins. The result of insulin resistance is high glucose in the blood, in an effort to store the excess glucose pancreas produces more insulin. obesity medicine This results into hyperinsulinemia and hyperglycemia.
Body mass index has a strong relationship to diabetes and insulin resistance.The development of diabetes becomes more inevitable if the failure of β-islet cells of the pancreas is accompanied by insulin resistance.
In obesity, there is a chronic and low-grade inflammation that is involved in the pathogenesis of several chronic diseases, such as type 2 diabetes, hypertension, atherosclerosis, fatty liver, cancer, asthma, and sleep apnea. The Association of obesity and inflammation has been reported more than 100 years ago. Inflammation is a physiological process characterized by an elevated number of white blood cells or increased levels of pro-inflammatory cytokines in the circulation or tissue. In general, inflammation is required for organ remodeling, tissue repairing, wound healing and immunity against infections. Inflammation is a protective reaction in the body to control harmful insults and to initiate the healing process. Overreaction of inflammatory response usually leads to multiple side effects such as tissue injury and organ dysfunction. obesity medicine Obesity-associated inflammation starts in adipose tissue and liver with elevated macrophage infiltration and expression of proinflammatory cytokines. The pro-inflammatory cytokines enter the bloodstream to cause systemic inflammation.
Weight gain and body mass are central to the formation and rising incidence of type 2 diabetes.
Congestive heart failure
Each unit increase in BMI increases the risk of congestive heart failure by 5% in men and 7% in women
Gallstone risk increases as BMI increases from 9% to 25% in women and 5% to 11% in men.
Stroke obesity medicine
For each increase of 1 unit BMI hemorrhagic stroke increases by 6% and ischemic stroke increases by 4%.
In proportion to the increase in body weight; decreases total lung capacity (TLC), forced vital capacity (FVC), and maximum voluntary ventilation (MVV).
Increased risk of asthma has been reported in an individual with an increase in BMI.
Alzheimer’s and dementia
Obesity at older ages increases the risk of Alzheimer’s and dementia in women. In women for every 1 unit increase in BMI at age 70 increases the risk for Alzheimer’s and dementia by 36%. These associations are more prevalent in women compared to men.
Obstructive sleep apnea (OSA)
Obstructive sleep apnea occurs in 50% of severely obese. Most people with OSA have BMI > 30. OSA is present in 90% of obese subjects seek bariatric surgery. Potentially it is life-threatening condition. OSA can cause serious CV complications. OSA causes chronic structural changes in coronary arteries leading to a possible increase in myocardial ischemia, and an increase risk of rupture of artery plaque and thrombosis.
Non-alcohol fatty liver disease (NAFLD)
NAFLD occurs in more than 66% of obese subjects. Truncal obesity is risk for NAFLD development even with normal BMI.
Obesity and caners
35% of cancers are attributable to dietary factors. A wealth of epidemiological data connecting obesity and various malignancies has suggested; postmenopausal breast cancer, colon, pancreas, gallbladder and gastric cardia.
Management of obesity
obesity are high a priority area for primary care practitioners because they are associated with many comorbidities.
What is healthy nutrition during weight loss
Water has so many uses in the body and is so essential for human life that it must be consumed daily for optimal function. A few of the important functions that water performs are dissolving nutrients to make them accessible to cells, assisting in moving nutrients through cells, keeping mucous membranes moist, lubricating joints, evaporating for body temperature regulation, and removing waste from the body. For most people, the daily water losses are about six cups (1.5 L) of urine, two cups (0.5 L) of sweat, and one cup (0.25 L) from breathing. In sum, about nine cups (2.25 L) are required for most people each day, but the body has many regulatory systems to allow for a wide variation in water intake. Interestingly, about 20% of the water is obtained from the water in food and is generated from metabolic processes. For practical purposes, the general recommendation to “drink when you are thirsty” will suffice during the weight loss process.
List of essential human nutrition
• Vitamins: A, B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B7 (biotin), B9 (folic acid), B12 (cyanocobalamin), C (ascorbic acid), D, E, K • Minerals: calcium, phosphorus, magnesium, iron • Trace minerals: zinc, copper, manganese, iodine, selenium, molybdenum, chromium • Electrolytes: sodium, potassium, chloride • Amino acids: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine • Essential fatty acids: linoleic, α-linolenic.
Protein is the major structural component of the human body. Dietary protein is the source of amino acids to provide the “building blocks” to make the proteins, and when used for energy, burned in a bomb calorimeter, contains 4 kcal/g.Picking the value of 1.5 g/kg/day, for adults with reference weights ranging from 60 to 80 kg, translates into total daily protein intakes 90 to 120 g/day. When expressed in the context of total daily energy expenditures of 2000 to 3000 kcal/day, about 15% of an individual’s daily energy expenditure (or intake if the diet is caloric) needs to be provided as protein. If calories are severely limited, then protein needs should be determined on a gram-per-kilogram basis. During weight loss, especially if strenuous exercise is a component of the process, more dietary protein may be advantageous.
A “tolerable upper limit intake level” is not set for total fat because there is no known level of fat at which an adverse effect occurs. Dietary fat may enhance fatty acid oxidation, and thus high-fat diets may be desirable to achieve the goal of dietary treatment of the obese individual. The optimal type of fat to eat during weight loss is not known, although recent evidence indicates that in the absence of carbohydrate intake (20 g or less/24 h) high-fat diets lead to lower levels of bloodstream saturates than in those eating a low-fat diet (11). (This may not be the case in calorie-restricted, low-fat diets.)
Carbohydrates are a source of energy containing 4 kcal/g when burned in a bomb calorimeter, and some single carbohydrates (monosaccharides) are used in physiologic compounds such as glycoproteins and mucopolysaccharides. While some dietary carbohydrates contain vitamins and minerals, there is no requirement for carbohydrates in the human diet because metabolic pathways exist within the body to make carbohydrates from dietary protein and fat. Dietary and endogenously created carbohydrate is stored as glycogen or converted to and stored as fat.
Source of Energy
To achieve lipolysis and increased fat oxidation in the dietary treatment of the obese individual, an important goal is to maximize fat as the major fuel source—fat from the diet and from adipose tissue stores. Carbohydrate then becomes a fuel source of much less importance because ketones (a metabolic product of lipolysis) can substitute for glucose in most tissues. Because carbohydrate used as a fuel is linked with lipogenesis, lipolysis and fat mobilization is reduced or halted when carbohydrate is a dominant fuel source. For optimal lipolysis and adipose tissue mobilization, keeping carbohydrates as an energy source to a minimum is preferable.
Essential Vitamins and Minerals
Dietary vitamins and minerals are required in small amounts and are found in food naturally. A few of the functions of vitamins include hormonal signaling and acting as mediators of cell signaling, regulators of cell and tissue growth and differentiation, precursors for enzymes, catalysts and coenzymes, and substrates in metabolism. Vitamins and minerals are now available in inexpensive pill and liquid form, and a “multivitamin” is recommended during weight loss, as a safety net.
Using nutritional ketosis as a diet therapy for obesity
Dietary carbohydrate is the primary insulin secretagogue. ” Several popular diets have used the recommendation of very low levels of carbohydrates (<20 g/day) in the early stages of the diet to enhance lipolysis. The presence of urinary ketones is an indicator of an increase in fat oxidation. Several research groups have referred to this approach as a “very low-carbohydrate ketogenic diet” (VLCKD) or “low-carbohydrate ketogenic diet”. When dietary carbohydrate is low (20 g/day), insulin larger amounts of weight loss have been reported.
The ketogenic diet is a high-fat, moderate protein, and low carbohydrates (carbs) diet that offer many health benefits. The ketogenic diet involves the replacement of carbs with fats. This reduction in carbs puts your body into a metabolic state called ketosis. During ketosis, your body becomes incredibly efficient at burning fat for energy. The ketogenic diet has numerous benefits. The body uses ketones as a source of fuel during metabolism. This process lowers blood glucose and insulin levels.
Fats are the best and preferred fuel for the human body. Therefore, in the ketogenic diet, 75% of the calories should be consumed from fats. To maintain the body’s muscle mass 20% of protein should be consumed. The body requires micronutrients for most of the enzyme functions. These can be obtained from vegetables, but from only those vegetables which are low in Glycemic index (GI). Vegetables have some carbs. Therefore, only net carbs of 20g are permittable in a daily diet.
Health benefits of the ketogenic diet:
Different studies have shown that the keto diet has several health benefits for a wide variety of different clinical conditions. A few of them are heart diseases, cancers, Alzheimer’s disease, epilepsy, polycystic ovarian, and Parkinson’s disease.
The glycemic index (GI) is a measure of the blood glucose-raising potential of the carbohydrate content of a food compared to a reference food (generally pure glucose). Relative to pure glucose food is classified as a high (≥70), moderate (<70 and ≥55), and low (<55) glycemic index.
Consumption of high-GI food causes a sharp rise in blood glucose concentration and insulin spikes. Insulin spike (in response to high glucose) causes a decline in blood glucose level.
Measuring glycemic index of food;
Factors affecting GI:
There are several factors that affect the human blood glucose levels of the carbohydrate-containing food in question. In other words, how fast, a particular carbohydrate releases glucose in the blood. These factors include the physical form of the food, chemical composition, and structure of carbohydrates in food.
The physical form of food
A particular food can have different GI in two different physical forms. For example, raw carrots have a GI of 71 but cooked carrots have a GI of 85.
The physical form of carbohydrates:
One of the factors that affect the ability of carbohydrates to release glucose in the blood is its physical form. For example, wheat flour and bread have higher GL compared to whole wheat. The higher GI value of wheat flour is due to the fact that flour and bread have a bigger surface area for digestive enzymes to act and metabolize them.
Chemical composition of carbohydrates:
All carbohydrates are different in their chemical composition. Glucose is the simplest form of carbohydrate. It has a GL value of 100.
By definition, the consumption of high-GI foods results in higher and more rapid increases in blood glucose concentrations than the consumption of low-GI foods. Rapid increases in blood glucose (resulting in hyperglycemia) are potent signals to the β-cells of the pancreas to increase insulin secretion. Over the next few hours, the increase in blood insulin concentration (hyperinsulinemia) induced by the consumption of high-GI foods may cause a sharp decrease in the concentration of glucose in blood (resulting in hypoglycemia). In contrast, the consumption of low-GI foods results in lower but more sustained increases in blood glucose and lower insulin demands on pancreatic β-cells.
An unpublished data has identified more physiological damage with sudden glucose spike and decline in blood compared to consistent high blood glucose concentration.
In other words, how quickly foods break down into sugar in your bloodstream. A food with a high GI raises blood sugar more than a food with a medium to low GI.
A GL value for food <10 is considered as low GL food, 10-20 as moderate and >20 as high GL food. Low GI food has little impact on blood glucose, moderate has moderate while high GL food has high impact of blood glucose and cause glucose spikes in blood.
Food ranked high on the GI may represent a huge portion of a food because GI is not based on standard serving sizes. However, the same food can have a low glycemic load because there may not actually be much total carbohydrate in a given serving of that food. A low GL is the better indicator that a food won’t have much impact on blood glucose levels.
For example: Watermelon has a high GI of 72, yet a low GL of 7.21. The high GI is based on 5 cups of watermelon, not an actual serving size of 1 cup. The low GL means one serving of watermelon doesn’t contain much carbohydrate, because it is actually mostly water. The low GL indicates that a serving of watermelon won’t have much impact on your blood sugar.
Glycemic load is dependent on the portion size. Sometimes it is difficult to consider the portion size while we are eating. It is highly likely that we might eat twice or even more of the permitted portion of a food that will account for low GL. Therefore, it is important to consider rather GI of the food as the indicator of blood glucose while making a healthier food choice.
Glycemic index verses glycemic load;
It is very important for diabetic people to know about the GL. As GL is dependent on the serving size. Different foods have different serving size. Next important thing for diabetic people is to have knowledge of serving size for their food of choice.
If you’re keen to learn about the GI and GL of your favorite foods, check out the University of Sydney’s glycemicindex.com website where you can put in almost any food and find out the values, depending on your serving size.