Abstract
Weight loss is a popular topic and may be of serious concern for many patients. Even with the abundant literature on obesity and cardiometabolic risk, it is always challenging to demystify and reinforce the determinants of safe approaches to lose weight. Measures of central obesity are essential to characterize the patient’s adiposity distribution and should be part of the routine medical examination. Beyond this, screening for fasting lipids and glucose are important for the assessment of the cardiometabolic risk which may lead to increased cardiovascular morbidity and mortality. Differences in adiposity as well as in weight loss exist between sexes and should be taken into consideration. Rather than avoiding some food or following certain type of diet, any planned weight loss interventions should promote lifestyle and environmental modifications with healthy eating and appropriate physical activity. With clear objectives, this appears to be the best way in order to achieve weight loss goals permanently.
Keywords
Weight loss, cardiovascular health, lifestyle, diet
Introduction
We are just starting 2015 and most of us probably heard of weight loss’ New Year’s resolutions. Body weight loss is known to improve metabolic profile, as well as reducing the risk of type 2 diabetes, hypertension, dyslipidemia and cardiovascular diseases. Following a recent systematic review conducted by an NHLBI Expert Panel, obesity guidelines were updated and published. We will take a look at Mr. Obe and Ms. Stiy’s stories, a couple in their late 50s, who both want to lose weight, but for different reasons.
Case number 1: Mr. Obe is retired from the military after 30 years of service. He enjoys his free time by either cutting grass or shoveling snow, as well as taking a 2-hour nap every afternoon. He claims that he trained so much in his career that he has got some credits for the remaining years of his life. He is used to being told by his wife to pay attention to what he eats; otherwise, he would get bigger year after year. He had not been paying much attention to his eating habits until he realized that he was not able to button his old shirt up anymore. As he is booked for his annual check-up with his family doctor next week, he will have the opportunity to discuss with him if he had better listen to his wife and lose some weight or buy a new shirt.
Case number 2: Ms Stiy works full time as a nursing assistant in a long-term care facility. In her mid-fifties, she feels very good. She manages to assist elderly people in their daily activities 40 hours a week. Of course, she is not as slim as she would like to be. She is the mother of three. This is the way she explains to herself her little “pot belly” that barely disappeared after the last pregnancy. Despite numerous diets, it even got bigger in the last few years. She plans to see her family doctor to discuss if, regarding her age and postmenopausal status, it is worth investing the effort in this brand new hypocaloric diet she read in her favorite magazine.
Through this paper, we will present an overview of the “in medical office” literature useful issues regarding obesity: adiposity measures, risks and benefits of weight loss as well as potential successful interventions to get out of the spiral loops of dieting and achieve long term weight loss success. Finally, we will integrate this knowledge to the above cases, highlighting differences among sexes on a background of a cardiovascular risk assessment note.
Is my patient really overweight/obese?
Different adiposity indexes can be used to assess a patient’s obesity. Depending on the index chosen, the information regarding cardiovascular risk associated to the patient’s excess weight can be different.
Body mass index (BMI)
BMI measurement assesses total body adiposity including fat mass and fat free mass without distinction between each other. BMI is the most popular indicator used to evaluate an individual obesity profile. BMI is calculated using weight in kilograms divided by height in meter squared (kg/m²). Important to know: it is more accurate for the clinician to measure height and weight at the visit during medical consultation in order to avoid possible height overestimation and weight underestimation if the values are self-reported. Overweight is defined as a BMI ≥ 25,0 kg/m² and obesity with a BMI ≥ 30,0 kg/m².
Waist circumference (WC)
WC is a good clinical assessment of abdominal adiposity, and is indicated as a complementary measurement of obesity. Many protocols may be used to measure WC (midpoint, umbilicus, iliac crest and minimal waist); they all provide similar cardiovascular risk estimate. However, it is important to use the same technique for a given individual’s follow-up. The iliac crest is the recommended landmark for WC because bony structures are not affected by weight changes. Acceptable cut points for WC are debated and they are ethnic specific. However, obesity guidelines states that WC thresholds for Caucasians, considered as a risk factor, should be > 35 inches (> 88 cm) for women and > 40 inches (> 102 cm) for men for identification of elevated cardiometabolic risk and potential complications.
Waist-to-hip ratio
Waist-to-hip ratio is a division of the WC by the hip circumference, which can be measured at the level of the widest circumference over the buttocks. This ratio helps the clinician to assess fat distribution, and distinguish between the android (more visceral fat accumulation) vs. the gyroid shape/fat distribution (more gluteo-femoral fat accumulation). The waist-to-hip ratio limits for Caucasians are ≤ 0,85 for women and ≤ 0,9 for men.
Waist-to-height ratio
Waist-to-height ratio is a division of the WC by height (cm). This ratio helps the clinician to quantify adiposity distribution depending on the individual height, without consideration of weight, age, sex or ethnicity. There is no published official threshold reference value for the weight-to-height ratio. Nevertheless, using WC and height mean values of different countries, a waist-to-height ratio below 0,51–0,58 for women and below 0,47–0,54 for men has been suggested to be a good parameter of central obesity and increased cardiovascular risk.
Is my patient at increased cardiovascular risk?
Obesity is generally defined as an excess of adipose tissue and is most often estimated by BMI. According to the Centers for Disease Control and Prevention, a BMI between 25,0 and 29,9 kg/m² and over 30,0 kg/m² are defined as overweight and obesity respectively. From a clinical perspective, evidence has shown positive association between obesity defined with BMI and cardiometabolic dysregulations including elevated blood pressure, insulin resistance, type 2 diabetes mellitus, dyslipidemia and cardiovascular disease. However, evaluation of the cardiometabolic risk profile should go beyond BMI. The distribution of adipose tissue should also be considered.
In men and women with normal adiposity in the presence of a positive energy balance, that is to say when caloric intake is greater than energy expenditure, energy surplus are stored in the subcutaneous adipose tissue where it acts as a sink. At first, this accumulation is associated with normal cardiometabolic risk profile. On the other hand, when the subcutaneous storage capacity becomes saturated or when there is a dysfunction in the storage process, energy surplus is stored as visceral adipose tissue. This process contributes to cardiometabolic alterations where the following deleterious adaptations could develop: insulin resistance, elevated blood pressure, low HDL-cholesterol, high small and dense LDL-cholesterol levels, inflammatory and prothrombotic states. Also, excessive accumulation of visceral adipose tissue is associated with deposition of adipose tissue at undesirables sites such as liver, pancreas, heart and skeletal muscles which result in lipotoxicity and may lead to organs dysfunction as well as the development of cardiometabolic health problems. Therefore, the addition of WC measurement to BMI is important to assess adipose tissue distribution and the cardiometabolic risk. For any BMI value, patient with a larger WC has more abdominal fat than a patient with a lower WC. This is a predictive parameter of an increased risk of hypertension, dyslipidemia, cardiovascular diseases and type 2 diabetes mellitus. Waist circumference measurement is an index of abdominal adiposity but it does not differentiate subcutaneous from visceral adiposity. To determine if one’s body composition and fat distribution is related to an increase in cardiometabolic risk, screening for lipids and glucose using fasting blood samples may be clinically useful and should be performed. Excess cardiovascular risk as well as need to lose weight for those with BMI ≥ 30,0 kg/m² or ≥ 27 kg/m² with at least one obesity-related risk factor, including WC, are identified by the obesity guidelines.
A hypertriglycerides state is known to be linked to elevated WC as well as visceral and ectopic fat deposition. This “hypertriglyceridemic waist” phenotype is associated with altered cardiometabolic risk profile and with poor clinical outcomes such as type 2 diabetes mellitus, cardiovascular diseases and increased mortality. Moreover, elevated circulating levels of triglycerides may be better predictors of cardiovascular disease (CVD) in women than in men.
Age and sex differences related to adiposity
Before menopause, there are major sex differences in visceral adiposity. Premenopausal women have, on average, 50% less visceral adipose tissue than men. This is clinically significant as subcutaneous fat tissue could be metabolically protective. This sex difference in visceral adiposity has been shown to mainly, but not completely, explain the gap between men and premenopausal women in terms of cardiometabolic risk profile. Regarding age, there is also a selective deposition of visceral adipose tissue that is predictive of the age-related deterioration in the cardiometabolic risk profile, particularly among those who have a family history of visceral obesity.
My patient looks healthy, would there be any benefits to weight loss?
Any intentional weight loss intervention aims to induce a negative energy balance. Even though methods employed may differ from one intervention to another, the goals should be to modify food intake, energy expenditure or both through healthy lifestyle and behavior modifications. Weight loss may induce several health benefits to an obese individual. Even more, it is known that a loss of only 5 to 10% of initial body weight is enough and is associated with health improvements. However, caution needs to be taken when planning weight loss; there could be potential negative effects that need to be addressed. Indeed, patients have a tendency to set difficult/impossible to reach goals in terms of weight loss. An objective of losing 30 to 40% of total body weight through non pharmacological/invasive approaches is quite unrealistic and unsafe.
A safe weight loss rhythm should be between 0,5 to 1 kg per week for 6 months. This way, someone who weighs 100 kg should aim at an initial weight loss of 10 kg, which would normally take 4 to 8 months (16 to 32 weeks) to reach. Besides, it is the second major recommendation of the obesity guidelines to support modest weight loss goals. Evidences showed that as little as 3–5% of weight loss benefits to glycemic and triglycerides parameters, while 5–10% produces additional improvements of the lipid profile (HDL and LDL-cholesterol), and both systolic and diastolic blood pressures. A reasonable weight loss could lead to metabolic profile improvements and then, prevention of chronic diseases. Metabolic profile will be enhanced by improving lipids profile as well as glucose tolerance. Blood pressure may also get lower with weight loss. It is important to note that all these beneficial effects will be seen in overweight individuals losing weight intentionally. An intentional weight loss should be, of course, voluntarily driven and should not be characterized by any health problem. Regarding psychological profile, improvements of self-esteem and satisfaction as well as quality of life could be observed after weight loss. These outcomes seem to be proportional to the weight loss itself.
Potential downsides could also be encountered after weight loss, even if it is intentional. These could affect muscular mass as well as bone density. In fact, both could diminish, leading to an increased risk of falls and fractures. This would translate into a poorer quality of life as well as an increased risk of mortality. Finally, weight loss objective should not be to end looking like the “ideal” thin body shape image as seen in magazines. A slow, but safe and individualized objective should be promoted. Weight loss intervention should always be considered to have positive and negative potentials effects and be personalized to each individual’s own physical and psychological health.
How many diets have you been on?
Diets overview
Many studies clearly demonstrate that popular diets do not work long term. Based upon calorie restriction, carbohydrate calculations or other “revolutionary methods”, most popular diets work for a short period of time but converge to weight regain after a while. Evidence reviewed in the obesity guidelines concluded that no one diet was superior in terms of weight loss. Of high importance, the fewest diets an individual has been on, the best are her/his chances to succeed with permanent weight loss. The message transmitted by health care professionals in this respect must be clear. Confusion occurs when legitimate experts disagree on important principles, such as the benefits of reducing dietary carbohydrates or in the case when well-founded recommendations appear to shift over time as new researches become available. As healthcare professional, one must remember that high levels of health literacy, media savvy and critical thinking skills are always required to distinguish information based on strong evidence from personal testimonials and biased communications and advertisements. Diets attract consumers. These consumers rely on a lot of non-scientific data to justify their weight loss method’s choice. Some beliefs are strongly rooted in traditional culture without being supported by scientific evidences. According to Thomas and al., the choice of a particular diet is frequently in response to family and/or friends recommendations. People tend to believe in information shouldered by celebrities they respect. A competitive range of celebrities, physical activity, psychology and pseudo-experts enjoy a nutrition specialist reputation without legitimate credit. These so-called experts are frequent sources for interviews regarding nutrition, and write the majority of popular books on food and diets, and so contributing to maintain food fads. Furthermore, slimness is frequently perceived as a synonymous of good health and well-being and becomes an ideal that individuals try to reach by any means. This perfectly characterizes the modern society which has the tendency to identify well-being by external circumstances instead of internal ones. According to Pelletier and al., individuals with controlled motivation (at the antipode of self-determined motivation based upon integrated reasons such as the importance of being healthy and the pleasure of eating healthily) will be very interested by popular diets promising a rapid change instead of a real call into the question of factors influencing weight regulation. The frame offered by popular diets is particularly attractive and reassuring for individuals showing a controlled motivation.
According to the Academy of Nutrition and Dietetics, the categorization of foods as «good or bad» promotes dichotomous thinking (judgment as either/or, black/white, all/none) and does not incorporate abstract or complex options into decision strategies. So, as long as one stays on a given diet (target behavior), the person feels a sense of perceived control (self-efficacy) and accomplishment. However, when encountering a tempting food, loss of control can occur, depending on the individual’s emotional state, inter-personal conflict and social pressure. The subject believes that there is not much that can be done once loss of control occurs. Consequently, it is not to the patient’s advantage to list in mid-air a few foods to banish from his alimentation. As explained with the total diet approach below and stated by the obesity guidelines, a supervised calorie restriction should be individualized for the patient’s health status (such as the DASH diet) and food-choices preferences. Diets with healthy food choices suiting patient’s tastes could be successful in inducing weight loss by negative energy balance.
Energy balance
Mathematically, weight loss is simple: the question is whether to create a negative energy balance, i.e. calories ingestion vs. energy spent. However, metabolic rate slows down with weight loss; this phenomenon is even more pronounced if the individual loses muscular mass. Thus, an individual who lost a few kilos could easily take them back if he/she goes back to bad habits. Between 2000 and 2006, federal recommendations stated that a reduction of energy intake by 478 calories, which equals to one hamburger, a regular beer with a bowl of 30 chips or a regular bacon, lettuce and tomato sandwich per day would result in a slow but steady weight loss of 0.5 kg per week. However, this recommendation was static and did not consider personalized dynamic changes in thermogenesis once the weight loss had started. Research on this topic is underway to investigate energy expenditure adaptation after weight loss and become even more precise with recommendations. Instead of maintaining obsessions towards caloric restriction and energy deficit, it is important to aim at a daily integration of healthy habits and to offer necessary support for those who progress towards caloric deficit, and weight/waist loss.
Lifestyle and environmental modifications
Promising nutritional interventions
Eating behaviors are determined by several factors. Among them, there are intrinsic biology and genetic, experiences with food, intra-personal (beliefs, attitudes, knowledge, aptitudes and social norms) and inter-personal factors (family, social network), so do environmental factors (food availability and accessibility, social environment, customs, material responsibilities, marketing practices, etc.). A real nutritional approach bound to success must lean on a global feeding model taking care of all these variables, instead of looking at a checklist of things to be done or to be eaten. A growing body of evidence supports recommendations to design behavior-oriented food and nutrition programs that are sustainable because they fit individual needs and preferences. Depending on the audience and situation, a variety of nutrition information, communication, promotion and educational strategies can be appropriate for efficient nutrition interventions. Nutrition information must be presented to provide consumers with a broader understanding of issues and to determine whether it applies to their unique needs. It is very important to avoid giving too much emphasis to a single food or food component, which can promote confusion and controversy rather than facilitate healthy dietary patterns for consumers to adopt. There is some controversy over many functional foods related to certain diseases or certain targeted objectives. Such is the case of trans fat (trans because of the hydrogenation of vegetable oils vs. the conjugated linoleic acid forms during bacterial biohydrogenation in the rumen of cows), white eggs or soybeans.
As presented by the Academy of Nutrition and Dietetics: Total Diet Approach to Healthy Eating, a balanced variety of nutrient-dense food and beverages should be consumed in moderation with adequate physical activity as the foundation of a health-promoting lifestyle. This is called “The total diet approach”. Based on overall eating patterns associated with important benefits, this total diet approach is also consistent with the fundamental principles of the 2010 Dietary Guidelines for Americans. A variety of non-federal organizations also support this approach, including the American Heart Association, the American Cancer Society and the American Diabetes Association. As such, the Mediterranean diet is a commonly accepted and healthful dietary pattern. A recent publication provides an update on the Mediterranean diet pyramid, which still includes at least 2 vegetables, 1 fruit, olive oil and breads or cereals at every main meal. It is important to emphasize that the Predimed trial have shown that the Mediterranean diet is associated with decreased cardiovascular events without substantial weight loss. These approaches promote pleasure of eating with specific food choices restricted only when based on scientific evidence. The concepts of moderation and proportionality are necessary components of a practical, action-oriented understanding of the total diet approach. The total diet approach, with its emphasis on long term eating habits and a contextual approach that incorporates nutrient-rich foods, provides more useful information to guide long term food choices. This approach recommends to limit intakes of foods that are high in saturated and trans fat so that the overall pattern of food and beverage intake meets needs without exceeding energy limits. Labeling specific foods in an overly simplistic manner as “good food” and “bad food” is not only inconsistent with the total diet approach, but it can cause many people to abandon efforts to make dietary improvements. Encouraged by many programs, Americans and Canadians should focus on sensible food choices instead of nutrient-dense foods and beverages, saturated and trans fat (solid fats), added sugars, sodium and alcohol food choices. Several indicators of nutrient quality have been summarized by the Academy: the Nutrient Rich Food Index, the profiling system proposed by the European Union, the Overall Nutrient Quality Index, and the “front-of-package rating system and symbols”. All of these are to help the public understand how to make food and beverage choices within a global nutritional context avoiding an exaggerated focus on a single kind of food as being good or bad.
According to the Academy of Nutrition and Dietetics, nutrition messages should focus on positive ways to make healthy food choices over time rather than strictly avoid individual foods. Energy density, defined as the amount of energy per unit of weight of a food or beverage should be considered. However, studies suggest that increasing awareness and providing nutrition education would not be enough to change eating patterns. Environmental factors modulation would be an interesting asset to include in a lifestyle program aiming at weight loss.
Environmental interventions
Even though lifestyle interventions are the most popular way to induce weight loss, it has also been shown that moderate environmental modifications can promote considerable weight loss. In a literature review, Brian Wansink demonstrates that environmental factors are as important as food choices, if not more, when one’s goal is to lose weight or only to stop overeating. In other words, someone would overeat, in part, because of the super-sized portions. We were taught to “clean our plate”, then ignoring satiety signals. In a two-arm interventional study where soup bowls were designed to be automatically refilled, it has been shown that the group with specifically-designed bowls ate 73% more than the group with regular bowls. Satiety is regulated in both, the short and long terms (within minutes to days later), either by sensorial, digestive or metabolic (hormonal) factors. It is a long process to regain our capacity to accurately listen to inners cues, such as satiety. In addition, it is somehow difficult to short-circuit habits by education. For these reasons, a potential solution by encouraging people to intervene on different environmental factors related to food consumption has been proposed. For example, large serving containers can increase how much a person will eat by 15–45%. These super-sized portions seem to suggest the “reasonable and appropriate” quantity to eat, out of conscious awareness of inner cues of satiety.
Role of physical activity in weight loss
As discussed earlier, weight control may be simply explained by the tight balance between energy expenditure and energy intake. A positive energy balance will result in weight gain while an increase in energy expenditure (as increment amount of physical activity) will lead to weight lost. Then, general recommendations for weight reduction should focus on both hypocaloric diet and exercise. Keeping the imbalance theory in mind, an increase in energy expenditure without any change in regards to diet should result in a negative energy balance and thus induce weight loss. Unfortunately, this equation is more complicated in real life: many other factors influencing weight loss intervene. Interventions focusing only on energy expenditure with a training program showed only small or no effect on weight reduction. There are three major hypothesis to explain this paradox in a healthy but sedentary population: 1) weight loss might be compensated be an increase in energy intake following exercise; 2) a sustained decrease in resting metabolic rate may occur following weight loss; and 3) an overall reduction in spontaneous activity can happen during resting time of the day, while not exercising.
Compensatory increase in energy intake is an important mechanism by which the actual weight loss may differ from the predicted weight loss. This phenomenon seems to be more related to women than men. Following an extensive training program of 40 weeks, women were more likely to compensate energy expenditure by increased energy intake. On the contrary, men had a tendency to decrease their energy intake following an exercise program. Consequently, men experimented significant weight loss, but not women. This compensatory pattern is also influenced by the amount of physical activity. In women, more calories spent per week were associated to higher compensatory energy intakes when compared to lower doses of exercise. Thus, women who had practiced higher amount of physical activity lost half of the predicted weight. Also, lean women are more affected by this compensatory increment in energy intake following exercise. They have a tendency to closely keep energy balance to zero. Fortunately, obese women are more likely to achieve a negative energy balance following long term moderate exercise training when compared to lean women.
The second hypothesis, involving a possible decrease in resting metabolic rate after exercise-induced weight loss, has been addressed in several studies and conclusions are still controversial. It has been reported that as long as body weight is maintained, there is no change in resting metabolic rate secondary to exercise. However, the twin-study of Bouchard et al. highlighted the possible existence of exercise-induced metabolic adaptation. In this study, metabolic rate at rest measured following exercise intervention was generally lower than the one calculated from fat free mass. Another study confirmed this data, suggesting that the body responds to a negative energy balance or weight loss by “energy preservation”. This compensatory mechanism in energy expenditure occurs in opposite ways regarding both weight gain or weight loss in order to maintain energy balance. Apart from weight loss, physical activity induces other health benefits, and moreover helps long-term maintenance of body weight loss. Even without any changes in body weight, significant changes in body composition arise with exercise. A significant reduction in body fat mass, mobilisation of adipose tissue and decrease in visceral adipose tissue is observed. Even if physical activity is not the most efficient tool in weight reduction, exercise plays a major role in weight management. Regular physical activity shows greater impacts preventing weight gain and maintaining weight loss. On the other hand, it might be feasible to lose weight with exercise alone, but a huge amount of physical activity would be required. In the 2008 American College of Sport Medicine Position Stand, it was mentioned that an amount of > 150 minutes/week of moderate physical activity is only associated with a modest weight loss (2–3 kg). However, a higher amount of physical activity (> 225–420 minutes/week) leads to greater weight loss (5–7.5 kg); clearly a dose-response exists. Additional benefits may be proportionally observed with additional amount of exercise.
For more concrete goal in terms of physical activity, pedometer may be used for a better motivation and adherence to a walking program. It has been reported that walking at least 7500 steps daily is associated with waist loss in patients with coronary artery disease. Of importance, weight loss intervention should include diet management and behavioral modification in addition to physical activity intervention for a better efficacy. According to the 2013 AHA/ACCTOS Guideline for the Management of Overweight and Obesity in Adults, any short-term weight loss intervention should include diet modification, physical activity, and behavior therapy. This would induce a weight loss up to 8 kg in 6 months if weekly onsite interventions are conducted by trained interventionists. After the first year, a continuous bimonthly (or more frequent) intervention is associated with a larger weight loss than any other usual care or intervention.
Behavior determinants of success
Most people are conscious of the importance of healthy diets and physical activity. As reported by the National Center for Chronic Disease Prevention and Health Promotion, most Americans do not meet the 2012 Dietary Guidelines for Americans (DGA): more than two third of adults reported not eating fruits or vegetables more than twice a day (67.5% and 73.7% respectively) and more than one third (36.2%) indicated no leisure-time physical activity. Regardless of the theoretical basis, messages are more likely to result in healthy dietary and lifestyle changes when they are consistent with a globally balanced and moderate dietary pattern. Information about behavior must be presented with sufficient details to provide patients with a broader understanding of issues and to determine whether it applies to their unique needs. Simply providing information can sometimes be effective in promoting healthy behavior, but communications are often more efficient when guided by healthy behavior-related theories and models. There is no best theory or models but analyses of dietary and physical activity data concluded that certain theoretical constructs (i.e. self-monitoring, prompting intervention formation, prompting goal setting, giving feedback and prompting review of behavioral goals) contribute to program effectiveness. In order to optimize communications and educational programs, appropriate theories and models of factors related to human behavior such as the “Knowledge-Attitude-Beliefs”, the Health Belief Model, the Transtheoretical Model, the Social Marketing, the Social Cognitive Theory, and the Socio-Ecological dimension, should be mastered and used. The Institute of Medicine as well as the Center for Disease Control and Prevention recommend the SMART approach, which is characterized by setting clear and precise objectives in order to be able to demonstrate a given achievement. With this approach, treatment objectives must be Specific, Measurable, Attainable, Relevant and Time Bound (SMART).
A cognitive strategy that people might use to find a balance between filling their immediate desires and adhering to their long-term goals is proposed. It is called the activation of compensatory beliefs (CBs). CBs are convictions that the negative impacts of a behavior can be compensated by the positive effects of another behavior (e.g. “I may eat this piece of cake; I’m going to the gym tonight, anyway”). Clinicians treating obesity should be sensitive to fluctuations in both motivational dimensions as they are likely to play a central role in determining long-term behavior and weight change.
Comprehensive lifestyle intervention programs
Put together, physical activity, diet and behavior modification should become a comprehensive lifestyle intervention program. Notably, one of the main recommendation from the obesity guidelines refers to patients entering into skills training to success with sustained lifestyle changes compatible with weight loss. As it takes hard work to create and sustain new behaviors, the guidelines recommend a treatment plan of at least a year. Concretely, they suggest to start intensively for the first half of the year, by a minimum of 14 face to face sessions (group or individual) with a trained interventionist. Obviously, access to such programs could be problematic for some patients and obesity guidelines also endorsed off-site programs using telephone or internet interaction.
Current medical therapies for weight loss
When weight loss is not successfully achieved, it may become necessary to add alternative treatments. Individuals with a BMI ≥ 30 kg/m² or ≥ 27 kg/m² with at least one obesity-related comorbidity may be considered potential candidates for pharmacotherapy. Available pharmacotherapies act either in the short term or the long term while influencing the brain or the gut. Short-term therapies are all sympathomimetic agents that should not be used more than 12 consecutive weeks as they may produce insomnia, dry mouth, asthenia, constipation, and increase blood pressure and heart rate. Available pharmacological agents are: Diethylpropion, Phentermine HCl, Benziphetamine and Phendimetrazine. There are only three approved long-term therapies on the market in the United States: Orlistat, Lorcaserin and phentermine/topiramate combination. Orlistat acts on the gut by inhibiting the intestinal digestion of fat. Lorcaserin works by activating serotonin 5-HT₂c receptors in the brain, then reducing fat and caloric intake. The last one is a combination of two molecules, phentermine and topiramate. The former is known to suppress appetite (sympathomimetic) while the latter is usually indicated to treat epilepsy and migraines. So far, these therapies seem to be relatively safe.
Bariatric surgery is indicated when lifestyle and pharmaceutical interventions have failed inducing weight loss. Individuals presenting a BMI ≥ 40 kg/m² or ≥ 35 kg/m², with at least one obesity-related comorbidity, would be potential candidates for bariatric surgery. Different techniques of bariatric surgery are currently available.
Differences between men and women
Obesity has a higher prevalence in women than in men in several countries. The gap is not so wide in USA: 36.8% of women over 20 years old are obese vs. 35.5% of men. Canadians population is less obese, with percentages of 23.5% and 27.6% respectively. Mexico has the greatest gap between both sexes as women are 34.5% obese and men, 24.2%. European countries tend to be less obese than North Americans, rarely exceeding 25% of obese individuals per sex. Also, it is well established that differences exist between men and women in terms of fat distribution. However, it is not obvious that same weight loss intervention would provide the same results for both sexes. Right from the start of adult years, men and women depicted different fat distribution. As men tend to gain weight around the waist (so-called android shape), women accumulate fat tissues around the thighs and buttocks, known as the gynoid shape. Even if popular thoughts aim to get rid of those saddlebags, this subcutaneous fat tissue depot has not been linked with increased cardiovascular risks or diseases. This way, one may assume that obese women depicting a gynoid shape would be protected on the long term vs. men regarding cardiovascular events. Unfortunately, it is not that simple. Menopause, which occurs around 50 years of age in most women, has a deleterious impact on fat distribution as body shape of postmenopausal obese women will change to an android shape. Men and postmenopausal women then become equal regarding cardiovascular disease risk. Indeed, this is one of the reasons explaining sex differences in targeted patients screening for lipids abnormalities. Percentage of total body fat would be higher in obese postmenopausal women compared to same age obese men. Lean body mass would be inversely correlated to change in total body fat mass and decrease significantly after menopause, which would contribute to a decreased basal metabolism rate as well as a declined in resting energy expenditure. This decline would also gradually be encountered in aging men. Drastic hormonal changes that occur with menopause may lead to increased appetite and decreased intention or willingness to be physically active which would certainly contribute to a positive energy balance (more energy ingested than spent) and weight gain. Exercise is of paramount importance to improve energy expenditure and promote a negative energy balance to lose weight. A drawback could characterize postmenopausal women who exercise: they tend to compensate more, from a diet viewpoint, than men after exercising. This may explain why women would not lose as much fat or weight as men for a given expense of energy.
Conclusion
Case number 1: Mr. Obe finally went to see his family doctor. His waist circumference was 102 cm and BMI was 32 kg/m². His doctor informed him that he now classified as “obese”. This sounded weird to the ears of this solid military man who trained all his life… before retirement, but now he had to admit it. That is what he needed to hear to trigger his willingness to really lose some weight. Keeping in mind the new guidelines for the prevention of cardiovascular disease, his doctor decides to order fasting lipid screening profile as well as fasting glycaemia and estimated glomerular filtration rate. His doctor encouraged him to start modifying his lifestyle and environment one step at a time and plan follow-ups regarding risk factor management.
Case number 2: Ms. Stiy, who is willing to lose weight, knew that none of the diets she tried in the past worked permanently. At one point, she has always gotten the weight back, and sometimes more than she weighed before. Her doctor discouraged her to start another drastic hypocaloric diet, even if Ms Stiy’s favorite actress succeeded in doing so, as testified in her fashion magazine. Another diet would just increase her long term risk of gaining weight. She was surprised to hear that diets are not the only part of the solution for a sustainable weight loss. Even more, her doctor told her that there are no “good or bad” foods, only healthy lifestyle. Actually, she realized she was pretty scared to discard any dietary plans she had ever known. On the other hand, she was ready and excited to open her mind to sensible food choice including her taste and preferences. To be ready to kick off her new lifestyle, they set a SMART objective together (Specific, Measurable, Attainable, Relevant and Time Bound) and organized follow ups for physical activity goals, and of course, progresses and encouragements.
An approach considering all the determinants of eating behavior and environmental factors seems to be the most promising intervention for sustainable weight loss. Even if postmenopausal women could reach their weight loss limits sooner than men of the same age, benefits on psychological and physical health are significant for both sexes. It is worth the efforts!