Understanding Obesity: Causes, Effects, and Dietary Solutions
It is well known that obesity is a serious health problem that poses a significant challenge to both individual and public health. It is a chronic, long-term health condition characterized by excessive body fat that may impair health. This serious health problem is a complex multifactorial trait and heritability studies indicate a strong genetic component that is facilitated by environmental factors. Obesity accounts for a large proportion of the worldwide non-communicable disease burden, including type 2 diabetes, cardiovascular disease, hypertension and certain cancers.
There are no specific symptoms associated with obesity. Excess abdominal (visceral) fat, particularly when it exceeds body fat in other areas, with a waist circumference greater than 40 inches (102 cm) for men or 35 inches (89 cm) for women, or a BMI over 30 can be considered a reliable indicator. In obese, abnormal accumulation of body fat takes place resulting in one or several health hazards. According to studies, obesity increases the risk of premature death by 1.45 to 2.76-fold and shortens lifespan by up to 20 years. Although there are several measures of adiposity in humans, the most commonly used to classify obesity is body mass index (BMI = weight [kg]/height [m]2). The BMI helps to assess potential health risks related to weight, as higher BMI values are often associated with increased risks of diseases like heart disease, diabetes, and certain cancers. Body fat levels can be assessed using BMI ranges as follows: 18.5 or below indicates underweight; 18.5 to <25 is normal weight; 25 to <30 is overweight; 30 to <35 is class 1 obesity; 35 to <40 is class 2 obesity; and 40 or above is class 3 obesity, also known as morbid, extreme, or severe obesity. However, BMI does not account for factors like muscle mass or fat distribution, so it should be used alongside other health assessments for a complete picture.
Another fact is that, establishing a clear link between eating habits and weight gain in individuals is very challenging. It is widely observed that some people seem able to eat freely without gaining weight. Although no one can consume unlimited calories without consequences, metabolic rates may vary from person to person, allowing those with faster metabolisms to eat more without gaining weight. The reverse is also true: if an individual's metabolism is slower than average, they may perceive that even minimal food intake leads to weight gain. This illustrates how two individuals with identical height, weight, body composition, age, and gender can burn calories at different rates.
Common Specific Souses of Obesity
It is usually a
combination of various genetic, lifestyle, and environmental causes that lead
to obesity. High-calorie diets, especially those rich in processed foods and
sugar, encourage superfluous calorie intake, while sedentary life reduces
energy use. Moreover, hormonal disturbances, such as insulin resistance or
chronically high levels of cortisol in response to chronic stress, make
conditions favorable for fat storage. Stress, depression, and emotional eating
may also be factors in overeating or choosing the wrong foods, aside from
these.
Further in this blog article, it is intended to mention all the causes along with dietary advices to manage and prevent obesity.
1 Metabolism refers to the countless chemical processes going on continuously inside the body that allow life and normal functioning.
1. Genetic Factors that Control Obesity
Genetics can affect how our body processes food into energy and how fat is stored. Some genes encourage weight gain through an increase in hunger and appetite, fat storage, and a reduction in metabolism.
Among the genes associated with obesity, the most influential gene associated with polygenic obesity is the fat-mass and obesity-associated gene (FTO), which was the first obesity gene variant identified using the genome-wide association study. The FTO gene and its many variants are believed to influence and respond strongly to food intake versus energy expenditure. Similar to the FTO gene, the melanocortin 4 receptor (MC4R) gene is implicated in increased body weight due to its influence on appetite and metabolism. The MC4R gene is crucial for regulating energy balance, appetite, and body weight. Family history also plays a very important role; if parents are obese, their children run a chance of being obese, as genetic similarities and patterns of living may be comparable.
Our genes may play a role in our metabolic rate . The technical term for this is our basal metabolic rate (BMR). The BMR is the number of calories our body needs to maintain basic functions at rest, like breathing and circulation. This rate is partially determined by our genes, but other factors such as age, gender, body composition (muscle mass vs. fat), hormone levels, and environmental temperature can influence your BMR as well. For example, muscle mass is an important factor. The greater the percentage of muscle mass we have, the faster our Basal Metabolic Rate (BMR) will be, resulting in a higher caloric intake requirement.
2. Epigenetics of obesity
The epigenetics of obesity examines how lifestyle factors—such as diet, physical activity, and environmental exposures—can influence gene expression without altering DNA sequences, contributing to the development of obesity. Epigenetic mechanisms, like DNA methylation and histone modification, can “switch on or off” certain genes involved in metabolism, appetite regulation, and fat storage. These changes may increase or decrease the risk of obesity and can sometimes be passed down to future generations. Research into epigenetics offers insight into how early-life interventions and lifestyle changes could potentially prevent or manage obesity.
2 Metabolism refers to the countless chemical processes going on continuously inside the body that allow life and normal functioning.
3. Growing older and obesity
Aging is associated with a shift in metabolic rate and body composition and a change in lifestyle that predisposes one to obesity. As age advances, the metabolic rate decreases, meaning the body burns fewer calories at rest. This can lead to weight gain even if eating habits remain unchanged. In addition, age-related muscle tissue loss decreases overall energy expenditure and leads to increased deposition of fat, especially visceral fat. Other factors include lifestyle ones, such as reduced physical activity and possible dietary shifts, which further increase the propensity to gain weight and diminish the ability to lose it as it ages.
4. Insufficient sleep and its link to obesity
It has been recorded that sleep deprivation is linked with an increased risk of obesity because sleep influences hormonal mechanisms involved in appetite regulation: ghrelin and leptin. Insufficient sleep increases the levels of ghrelin that signal appetite, whereas on the other hand, it suppresses leptin (“satiety hormone”) levels that signal fullness, hence, resulting in overeating. In addition, sleep loss can result in a lack of energy, thus diminishing physical activities and evoking cravings for food with high calorie content, which further promotes weight gain.
5. Elevated stress levels and their association with obesity
High levels of stress may further lead to obesity through the release of cortisol, a hormone responsible for fat storage, particularly in the abdominal region. Stress also heightens emotional eating-where people find comfort in high-calorie food; this mostly results in excessive calorie intake. Chronic stress may reduce one's motivation for physical activity, further exacerbating weight gain and complicating healthy lifestyle maintenance. Anxiety and depression may also contribute to obesity, as they can induce hormonal changes that increase cravings for junk food.
6. Pregnancy and its relationship with obesity
Pregnancy may be influenced by obesity, through hormonal changes and increased nutritional demands that may precede it. While a normal weight gain constitutes a fact and is usually necessary in pregnancy, excessive weight gain increases the risk of obesity later in life for both mother and child. Moreover, hormonal changes and lifestyle adjustments make it difficult for new mothers to get back into their pre-pregnancy weights. Healthy nutrition and physical activity throughout and after the pregnancy are both very important to prevent unnecessary weight gain and promote general health.
7. Environmental Influences on Obesity
Another very important cause of obesity seems to be environmental influence, since it basically influences nutrition and physical activity, and hence the general pattern of life. The presence of high-calorie foods processed and available in neighborhoods can increase a pattern of poor eating, whereas a lack of safe areas for exercise can decrease the possibilities of physical activity. Moreover, advertisements and marketing focus on high-calorie foods, promoting poor nutrition habits. Thus, socioeconomic status can also determine obesity: people in low-income areas might be deprived of healthy food and means for a healthy lifestyle.
Biochemistry and Physiological Aspects of Obesity
While biochemical changes in the body can also lead to obesity, hormones such as insulin and leptin control appetite and fat storage. In obese individuals, cells can become resistant to insulin, causing blood sugar levels to rise and making fat storage more challenging. Normally, leptin ("satiety hormone") sends signals to the brain indicating fullness. However, this physiological response may be impaired in obesity, leading to overeating due to leptin resistance. Moreover, fat cells deposited around the waist secrete inflammatory chemicals that disrupt normal biochemical processes and affect vital organs like the heart and liver. Energy balance is another important factor; when a person consumes more calories than needed, the excess calories are ultimately stored as fat, leading to weight gain.
3 Ghrelin is a hormone produced primarily in the stomach that stimulates appetite and promotes food intake by signalling hunger to the brain.
4 Leptin is a hormone produced by adipose (fat) tissue that helps regulate energy balance by signalling satiety to the brain, thereby inhibiting hunger and promoting energy expenditure.
Consequences of Obesity
Obesity may cause severe health complications, which may badly affect the both physical and mental well-being. It may increase the risk of acquiring chronic diseases such as type 2 diabetes, hypertension, and cardiovascular diseases, further resulting in severe health complications. This can also lead to various joint disorders, such as osteoarthritis, due to the additional stress placed on the joints. The psychological effects are also significant, as obese individuals often experience low self-esteem, anxiety, and depression, which can perpetuate unhealthy behaviors. Also, it reduces one's quality of life due to limited mobility and fast tiredness.
Dietary Remedies for the Treatment and Prevention of Obesity
We could get adequate nutrition without overconsumption of calories by returning to a balanced diet focused on fruits, vegetables, whole grains, and lean proteins. To avoid overeating, control portions by using smaller plates and not distractedly eating in front of the television. Lowering the consumption of processed foods and sugary drinks cuts calorie intake and makes a big difference in lessening insulin resistance. High-fiber food, fruits, vegetables, and whole grains ingested in meals induce feelings of satiety and control appetite. Nutritious meal consumption on time diminishes curiosity about binge eating, and proper hydration could replace snacking for no reason at all and contribute to the entire body's functioning as well. These diet remedies would ultimately enable us to advance toward the habituation of healthy practices, hence leading to a path toward the effective management and prevention of obesity.
Best wishes for a healthy life!
University of Sri Jayewardenepura