Professional certification from the International Association for the Study of Obesity for the prevention and cure of obesity
Obesity is defined as that medical condition whereby the body has accumulated so much excess fat that the individual’s health is seriously jeopardized. It is roughly determined by the Body Mass Index (BMI) whereby the person’s weight in kilos is divided by his height in meters squared (kg/m2).
Thus, among adults:
- Obesity is considered to be a BMI of >30 kg/m2
- Overweight is considered a BMI of >25 kg/m2
- Normal weight is considered to be a ΒΜΙ of between 18.5 kg/m2 and 25 kg/m2
- Underweight is considered to be a BMI of less than 18.5 kg/m2.
Composition and function of fat tissue
Fat tissue is made up of adipocytes that store triglycerides from the circulation and convert them into other essential forms of energy essential for the body. They also secrete various hormones and cytokines which impact:
– glucose metabolism
– lipids / cholesterol metabolism
– arterial pressure
– fertility in women
– the functioning of vessels
– the heart
– the appetite
– energy burning of the body
– the body’s response to stress
– immunity, the body’s defence system
– brain functioning
The adipocytes swell when they store large quantities of fat, while they also multiply when bodily needs are increased (hyperplasia and hypertrophy of fat tissue).
The health risks of obesity
Obesity is especially dangerous for the health when the increased fat storage takes place in the belly/abdomen –this known as central, visceral or abdominal fat / obesity. When the adipocytes of visceral fat swell, their functioning becomes non-normal and they produce hormones and peptides that induce:
– diabetes mellitus / sugar diabetes
– gestational diabetes
– elevated fat counts
– reduction of fertility in men and women
– negative impact on metabolism, i.e. the body’s fat burning abilities
– cardiovascular disease and coronary heart disease
– certain types of cancer
– erectile dysfunction
Note: An unhealthy diet increases the risk of brain degeneration and thus of the development of dementia.
The causes of obesity
Fat, which is an active endocrinological gland, is susceptible to both internal and external stimuli.
The main causes of obesity are the following:
• the type of diet
• a change in one’s daily habits as to mealtimes
• lack of time to cook at home
• stress, depression, anxiety
• lack of sleep
• a sedentary lifestyle and lack of exercise
Weight loss is achieved via:
Α) development of a diet tailored to each patient in accordance with their medical history, distribution of fat and of other body tissues, basal metabolism (calories burned in the resting state)
Β) slimming / weight-loss products (these are in research trials)
C) bariatric surgery, the specific method of surgery being determined according to the individual patient
The aim of weight loss is different for each individual patient (according to the subject’s fat distribution) and of other body tissues as well as the patient’s basal metabolism (calories burned in the resting state).
Changes during weight loss and aims
One way to achieve weight loss is via intake of calories fewer than those habitually consumed in total. However, when a person’s intake of calories is significantly lower, i.e. less than those of his/her basal metabolism, as for instance when following a low-calorie diet, below 1200 calories, the body inevitably reacts. It goes ‘on the defensive’ through hormonal changes guarding against what could be malnourishment when, in fact, the person is purposely dieting in order to lose weight. Thus, “energy conservation” comes about to help the body deal with the apparent condition of starvation. It is important to realize that fat burning is the result of hormonal changes. When the individual loses weight, his metabolism may drop. This should not be regarded as disturbing since reduction of metabolism is the result of tissue loss.
With proper nutrition, it is possible to conserve one’s metabolism and one’s initial fast rate of fat loss at an optimum level. Weight reduction ideally involves an analogous substantial loss of adipose tissue. Importantly, loss of muscle tissue may be avoided by undertaking muscle-strengthening activities during a weight loss programme. In the course of a weight loss programme, the body’s metabolism may be reduced as a response to the lower intake of calories, a state which most people go through without being aware of it. It is well known that weight loss can be easily achieved for the first kilos, but it becomes increasingly harder as time goes on, while the subject may come up against a worrying plateau in those cases when the loss mainly concerns the shedding of fat. When a lower metabolism is reached, the intake of food must be adjusted or activity must be increased so that the shedding of the remaining weight may be continued. During the weight loss programme, all changes in metabolism will be closely monitored by the attending physician and any necessary adjustments will be made as to nutritional intake in order that successful weight management may be achieved. In addition, there will be constant monitoring of changes in body composition for successful attainment of fat loss.
What is meant by weight loss?
The achievement of successful weight loss requires the intake of proper food components through one’s diet, which will:
a) conserve hydration
b) improve the functioning of vessels
c) preserve bone mass
d) improve lipids in the blood
e) improve sugar levels
f) improve the functioning of menstrual flow and of female hormones
g) reduce the risk of the development of cancer
h) reduce the risk of the development of cardiovascular events
e) reduce the risk of dementia
Analysis of body composition
A full analysis of changes in body composition in each region of the body is undertaken, such as of visceral fat and the changes this undergoes.
With the right diet, it is possible to conserve the individual’s metabolism as well as the initial rapid rate of fat loss. Weight reduction ideally involves an analogously substantial loss of adipose tissue.
This is why continual monitoring of changes in body composition is essential so that the regimen may be adjusted in accordance with these changes and in order to quantitatively alter hormone secretion and to maintain fat loss and the metabolic rate.
Resting Metabolic Rate (RMR)
Α) What is this?
RMR denotes the minimum amount of calories that need to be consumed by the body in order to maintain vital functions: RMR records the number of calories consumed when a person is at complete rest (reclining with relaxed muscles): anything that is done during a typical day needs the burning of calories in addition to those burnt to support the resting metabolic rate.
Β) How is it done?
The BMR calculator will estimate the basal metabolism, i.e. the amount of calories burnt based on the patient’s body functioning while he is at complete rest. Employing the most up-to-date BMR calculator, the patient’s oxygen consumption is calculated with great precision and the individuals’ minimum energy needs are determined.
C) Why is it needed?
BMR calculation takes places in order to increase the likelihood of weight loss. Without an examination of basal metabolism rate, it is not possible to accurately calculate the calories that need to be consumed for the individual to reduce his weight. Another reason is to calculate the changes brought about in basal metabolism during weight loss as well as to ascertain its values at the end of the programme and during maintenance, since it acquaints us with the rate of any weight regain that may follow weight loss.
D) Factors influencing basal metabolism
Basal metabolism differs from person to person, since it is affected by a large number of factors. Some of these are:
– Age: As a person ages, his basal metabolism declines. Thus, in adults, it drops by 2% per decade.
– Gene profile: Some people are genetically at an advantage as they naturally have a high metabolic rate.
– Gender: Normally, men have a higher metabolic rate than women on account of their greater muscle mass.
– Body composition: In general, the greater an individual’s muscle mass, the higher will be their basal metabolism. Thus, while in general men’s basal metabolism is higher than that of women, female athletes have a higher basal metabolism than women leading a sedentary life because of their higher percentage of lean muscle mass.
– Body surface: Large-bodied persons lose more heat through body perspiration, which explains why they have greater energy needs.
– Endocrine glands: Most particularly endocrine secretions of thyroxine, insulin, glucagon, cortisol, etc. will influence basal metabolism.
– Special conditions: These include pregnancy which is accompanied by a rise in basal metabolism because of the increase in muscle mass (the womb, the placenta and the foetus), as well as of hormones. Also, stress and injury conditions.
– Nutrition: Malnutrition, intense fasting and exhausting diets reduce the basal metabolism by as much as 20%. In addition, frequent alternations in food deprivation, eating abuse and constant fluctuations in weight (the yoyo effect) induce a significant long-term decrease.
– Stress: A clear link between stress and obesity has been conclusively established. People suffering from stress typically turn to sugar- and fat-laden ‘comfort foods’ which boost serotonin, a mood-elevating chemical. In addition, stress may increase cortisol, which further promotes cravings for fatty and sugary foods, while neuropeptide Y, a chemical released during periods of stress, encourages fat accumulation.
Bariatric surgery in the management of obesity
Who is eligible for this?
Bariatric surgery for obesity should be a last resort; it is intended for obese patients who have a BMI of over 40 kg/m2, or for overweight persons who have a BMI of 35 kg/m2 along with hypertension and/or hyperlipidaemia.
It must first be preceded by a period of weight loss through a diet programme whereby the patient will show that he/she has been instructed in the difficult demands of the regime that will follow the bariatric intervention.
What interventions are available?
The type of surgery to be undertaken differs from case to case according to the patient’s medical history. There will be a discussion not only with a specialist surgeon but also with a physician specialized in metabolic disorders.
Α) Sleeve gastrectomy
During this intervention, a large portion (approximately 85%) of the stomach is removed while forming the remaining stomach into a tube or sleeve, without however the function of digestion and absorption of nutrients being essentially disrupted. The section of the stomach to be removed is cut and sewn together simultaneously.
Β) Gastric banding
An adjustable band is placed around the upper part of the stomach in order to obstruct the passage of large quantities of food. During the first post-surgery months following its placement, food must be strained and taken in small quantities. The patient must have no history of alcoholism or psychic illness and needs to have much self-discipline. If the patient attempts to eat large quantities of food, he will suffer pain and vomiting. Such food as ice creams and soft drinks and high-sugar drinks that pass through the band easily should be avoided to prevent the consumption of excess calories. Another problem to be avoided is when the patient gradually begins to eat more: the band then starts to loosen permitting the passage of greater amounts of food, thus placing at risk the patient’s weight loss target. Close monitoring by the physician specialized in metabolic disorders is therefore mandatory.
C) Biliopancreatic diversion
This is a malabsorptive mode of surgery. The surgeon cuts away a large section of the stomach and then connects it with a part of the intestine at a lower point, thus bypassing a section of the gastrointestinal tract. In this manner there is, on the one hand, restriction of food intake, while on the other, malabsorption of nutrients is achieved, and most especially of fats, which ultimately results in a significant reduction in the intake of calories.
It constitutes the intervention of choice for persons who are morbidly obese with a BMI of >40, since it produces the best results and has a weight loss success rate of 80-90%. The intervention is irreversible and changes in the intestine brought about by the surgery are permanent.
D) Gastric bypass: Roux-en-Y gastric bypass (RYGBP)
In this type, the stomach is reduced to a small ‘pouch’ in the upper section, while the much larger lower remnant is left intact, the result being that stomach capacity is greatly reduced. This comprises the restrictive part of the intervention. Following this, the small segment is connected with a rather more distant section of the intestine, resulting in a change in the physiology of digestion and the absorption of food. Via this combination, highly successful weight loss is achieved by the morbidly obese.
Nutritional support following bariatric surgery
After malabsorptive bariatric surgery, special nutrition is required as well as supplements to ensure sufficiency in vitamin and essential elements. Close monitoring of metabolic changes is carried out by the physician specialized in metabolic disorders.
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