| Part of a series on |
| Human body weight |
|---|
While genetic influences are important to understanding obesity, they cannot explain the current dramatic increase seen within specific countries or globally. [1] It is accepted that calorie consumption in excess of calorie expenditure leads to obesity; however, what has caused shifts in these two factors on a global scale is much debated.
The correlation between social class and body mass index (BMI) varies globally. A review in 1989 found that in developed countries women of a high social class were less likely to be obese. No significant differences were seen among men of different social classes. In the developing world, women, men, and children from high social classes had greater rates of obesity. [2] An update of this review carried out in 2007 found the same relationships, but they were weaker. The decrease in strength of correlation was felt to be due to the effects of globalization. [3]
Many explanations have been put forth for associations between BMI and social class. It is thought that in developed countries, the wealthy are able to afford more nutritious food, they are under greater social pressure to remain slim, and have more opportunities along with greater expectations for physical fitness. In undeveloped countries the ability to afford food, high energy expenditure with physical labor, and cultural values favoring a larger body size are believed to contribute to the observed patterns. [3] Attitudes toward body mass held by people in one's life may also play a role in obesity. A correlation in BMI changes over time has been found between friends, siblings, and spouses. [4]
The term "food desert" was reputedly first used by a resident of a public sector housing scheme in the west of Scotland in the early 1990s to capture the experience of living in a deprived neighborhood where food was expensive and relatively unobtainable. The phrase first appeared in an "official" publication in 1995, as part of a report from a policy working group investigating grocery distribution and food retailing on behalf of the Low Income Project Team of the UK government's Nutrition Task Force. [5] The term "food desert" is used to "describe populated urban areas where residents do not have access to an affordable and healthy diet." Reports have "suggested that food deserts may damage public health by restricting the availability and affordability of foods that form the components of a healthy diet." [6] Nicole I. Larson and her colleagues did a research review to relate obesity with neighborhood environments. They argue that "availability of fast-food restaurants and energy-dense foods has been found to be greater in lower-income and minority neighborhoods." When neighborhoods have more access to supermarkets with fresh produce there is a decrease in unhealthy dietary habits and levels of obesity. "Low-income, minority, and rural neighborhoods" are affected the most by this little access to supermarkets and tend to have greater access to fast-food restaurants and convenience stores with energy-dense food. [7] For example, one study found that high-poverty areas and all African American areas (regardless of income) were less likely than predominantly white higher-income communities to have access to foods that enable individuals to make healthy choices. [8]
However, some recent studies have not been able to confirm the claims that distance to supermarkets predicts obesity or even diet quality. [9]
Stress and emotional brain networks foster eating behaviors that may lead to obesity. The neural networks underlying the complex interactions among stressors, body, brain and food intake are now better understood. Stressors, by activating a neural stress-response network, bias cognition toward increased emotional activity and degraded executive function. This causes formed habits to be used rather than a cognitive appraisal of responses. Stress also induces secretion of both glucocorticoids, which increases motivation for food, and insulin. Pleasurable feeding then reduces activity in the stress-response network, reinforcing the feeding habit. [10]
One study found that "higher work stress was associated with higher consumption of specific fatty foods among men but not women." [11]
In another study done by Richardson and her colleagues, "a sample of low-income women with children, we found that perceived stress was directly and positively associated with severe obesity, independent of eating behaviors and diet quality. In addition, perceived stress was directly and positively associated with unhealthy eating behaviors." [12]
A study done by Shaikh and colleagues found that "in both unadjusted and adjusted analyses, lower levels of education and incomes were generally associated with higher likelihood of obesity and higher mean BMI." [13] Shaikh and his colleagues gathered data from the US National Health Interview Survey about 23,434 adults. With that information, the researchers conducted regression analyses to depict obesity in relation to different socioeconomic parts, such as education. With a P value <.001, they found that obesity was less common in adults with a higher educational attainment versus those with a lower educational attainment. They concluded that education and obesity are highly associated and their call to action was for public schools to have more health education. [14]
Similarly, in a study done in Germany, researchers found that "indicators of parental education were most strongly associated with children's obesity. There was a strong dose–response relationship between a composed index of social class and obesity. Children of the lowest social status had a more than three-fold risk to be obese than children of the highest social status in the screening population." [15]
Social context associated with meal-time plays a key role in factors involved with obesity. Studies have shown the effects of family meal- time in relation to childhood obesity. A study done by Jerica Berge [16] looked only that the interactions at meal times with families and neglected the types of foods they were eating. The results showed that families who ate one or two meals together had lower rates of obesity. In conjunction to eating a meal together, the results showed that table conversations and family dynamics play key roles in lowering the rates of obesity in child and adults. The families who enjoy spending time together, create a sense of cohesion among each other. Family meal-time is a place where everyone can talk about their day and parents provide a positive environment for their children. Positive reinforcements included telling their children if they eat their food they will grow up to be strong and fast. By family members asking about each other day, especially to their child, they see that someone is expressing interest in their life and that they care. [17] The more positive communication there is at the table the lesser amount of food a person will consume. Slowing down your eating is helpful in both losing weight and keeping healthy eating habits because it always your brain too caught up with your eating and signals that you are full sooner. Children will develop these eating habits that reflect a healthy living style demonstrated from their parents and/or other family members.
The group that showed an increase of obesity rates was the family who spent little time together and/or when they did it was a hostile environment. Parents who were more controlling about what and how much their child ate showed an increase their obesity rates. A study done by Heather Patrick [18] showed that this type of feeding style, referred to as authoritarian feeding, has the opposite effect on children's eating habits. In this article, researchers found that limiting or prohibiting a child's access to foods high in fat, sugar, and energy led to the desire to overeat these "forbidden" foods. It creates a sense of anxiety within the child which can lead into them feeling insecure lowering their self-esteem. Children and adults eating in this type of environment also tend to use technology, like being on their phones or watching television, at the table distracting each other from engaging in conversation. Not only was there less communication going on but they also over consume due to mindless eating contributing to the increase of obesity rates in these types of families.
Many studies have demonstrated the effects of social facilitation. In 1972, researchers Nisbett and Storms invited subjects to eat crackers stating that it was a "taste test". Subjects tasted the crackers alone or were partnered with a confederate who ate either 1 or 20 crackers. Normal-weight subjects ate 29% less with the low-intake model and 25% more with the high-intake model than when alone. In 1979, Polivy et al. invited subjects who had fasted for five hours to eat sandwich quarters. When the subjects were paired with a confederate who ingested eight sandwich quarters, subjects consumed 57% more than when the confederate only ate two quarters.
Those who quit smoking gain an average of 4.4 kilograms (9.7 lb) for men and 5.0 kilograms (11.0 lb) for women over ten years. [19] Changing rates of smoking, however, have had little effect on the overall rates of obesity. [20]
A study done by Sucharda found that if there is smoking in families or maternal smoking, the children are put at a higher risk for obesity. [21]
Label literacy in important for people to understand nutritional facts about the foods they eat. In a research study done by Kennen and her colleagues, they sampled 210 obese adult patients at a primary care clinic and determined their literacy levels with a literacy screening instrument. With a p-value of <.05, they found a significant correlation between weight loss knowledge and literacy level. Two out of every three obese patients read below a 9th grade reading level. With these results, they came to the conclusion that the lower literacy a person has, the less knowledgeable they are in regards to the health effects associated with obesity and the more likely they are to underestimate the need to lose weight. [22]
Malnutrition in early life is believed to play a role in the rising rates of obesity in the developing world. [23] Endocrine changes that occur during periods of malnutrition may promote the storage of fat once more calories become available. [23]
In the United States the number of children a person has had is related to their risk of obesity. A woman's risk of obesity increases by 7% per child, while a man's risk increases by 4% per child. [24] This could be partly explained by the fact that having dependent children decreases physical activity in Western parents. [25]
In the developing world urbanization is playing a role in increasing rate of obesity. In China, overall rates of obesity are below 5%. However, in some cities, rates of obesity are greater than 20%. [26]
Globalization has made cheap fatty food available in all the nations, greatly increasing fat intake all over the world. "Fast food chains and vending machines packed with lipid-rich foods as well as high calorie sodas can now be found in Santo Domingo, Dominican Republic and East Oakland, California alike". [27]
There is a debate about the fact that globalization contributes to the obesity pandemics. A 2013 cross sectional review showed that, in high income countries, the global increase in BMI is positively associated with both the index of economic globalization and inequality between countries, after adjustment for covariates. [28] a contrario, a 2017 empirical study demonstrates that globalization, including trade openness, FDI flows, and economic freedom reduce weight gain and obesity among children and youth, supporting the proposition that globalized countries prioritize health because of the importance of labor productivity and human capital due to heightened market competition, ceteris paribus, even if rising incomes might drive high consumption. [29]
Obesity is a medical condition, sometimes considered a disease, in which excess body fat has accumulated to such an extent that it can potentially have negative affects on health. People are classified as obese when their body mass index (BMI)—a person's weight divided by the square of the person's height—is over 30 kg/m2; the range 25–30 kg/m2 is defined as overweight. Some East Asian countries use lower values to calculate obesity. Obesity is a major cause of disability and is correlated with various diseases and conditions, particularly cardiovascular diseases, type 2 diabetes, obstructive sleep apnea, certain types of cancer, and osteoarthritis.
Childhood obesity is a condition where excess body fat negatively affects a child's health or well-being. As methods to determine body fat directly are difficult, the diagnosis of obesity is often based on BMI. Due to the rising prevalence of obesity in children and its many adverse health effects it is being recognized as a serious public health concern. The term 'overweight' rather than 'obese' is often used when discussing childhood obesity, as it is less stigmatizing, although the term 'overweight' can also refer to a different BMI category. The prevalence of childhood obesity is known to differ by sex and gender.
Obesity in Mexico is a relatively recent phenomenon, having been widespread since the 1980s with the introduction of ultra-processed food into much of the Mexican food market. Prior to that, dietary issues were limited to under and malnutrition, which is still a problem in various parts of the country. Following trends already ongoing in other parts of the world, Mexicans have been foregoing the traditional Mexican diet high in whole grains, fruits, legumes and vegetables in favor of a diet with more animal products and ultra-processed foods. It has seen dietary energy intake and rates of overweight and obese people rise with seven out of ten at least overweight and a third clinically obese.
Obesity is common in the United States and is a major health issue associated with numerous diseases, specifically an increased risk of certain types of cancer, coronary artery disease, type 2 diabetes, stroke, and cardiovascular disease, as well as significant increases in early mortality and economic costs.
Being overweight or fat is having more body fat than is optimally healthy. Being overweight is especially common where food supplies are plentiful and lifestyles are sedentary.
Obesity has been observed throughout human history. Many early depictions of the human form in art and sculpture appear obese. However, it was not until the 20th century that obesity became common — so much so that, in 1997, the World Health Organization (WHO) formally recognized obesity as a global epidemic and estimated that the worldwide prevalence of obesity has nearly tripled since 1975. Obesity is defined as having a body mass index (BMI) greater than or equal to 30 kg/m2, and in June 2013 the American Medical Association classified it as a disease.
Obesity in Canada is a growing health concern, which is "expected to surpass smoking as the leading cause of preventable morbidity and mortality" and represents a burden of Can$3.96 (US$3.04/€2.75) billion on the Canadian economy each year."
Despite India's 50% increase in GDP since 2013, more than one third of the world's malnourished children live in India. Among these, half of the children under three years old are underweight.
Diet plays an important role in the genesis of obesity. Personal choices, food advertising, social customs and cultural influences, as well as food availability and pricing all play a role in determining what and how much an individual eats.
Weight management refers to behaviors, techniques, and physiological processes that contribute to a person's ability to attain and maintain a healthy weight. Most weight management techniques encompass long-term lifestyle strategies that promote healthy eating and daily physical activity. Moreover, weight management involves developing meaningful ways to track weight over time and to identify ideal body weights for different individuals.
Research into food choice investigates how people select the food they eat. An interdisciplinary topic, food choice comprises psychological and sociological aspects, economic issues and sensory aspects.
Obesity in the Middle East and North Africa is a notable health issue. Out of the fifteen fattest nations in the world as of 2014, 5 were located in the Middle East and North Africa region.
The term "Freshman 15" is an expression commonly used in the United States and Canada that refers to an amount of weight gained during a student's first year at college. In Australia and New Zealand, it is sometimes referred to as "First Year Fatties", "Fresher Spread", or "Fresher Five", the latter referring to a five-kilogram gain.
Criticism of fast food includes claims of negative health effects, animal cruelty, cases of worker exploitation, children-targeted marketing and claims of cultural degradation via shifts in people's eating patterns away from traditional foods. Fast food chains have come under fire from consumer groups, such as the Center for Science in the Public Interest, a longtime fast food critic over issues such as caloric content, trans fats and portion sizes. Social scientists have highlighted how the prominence of fast food narratives in popular urban legends suggests that modern consumers have an ambivalent relationship with fast food, particularly in relation to children.
Social class differences in food consumption refers to how the quantity and quality of food varies according to a person's social status or position in the social hierarchy. Various disciplines, including social, psychological, nutritional, and public health sciences, have examined this topic. Social class can be examined according to defining factors — education, income, or occupational status — or subjective components, like perceived rank in society.
School meals are provided free of charge, or at a government-subsidized price, to United States students from low-income families. These free or subsidized meals have the potential to increase household food security, which can improve children's health and expand their educational opportunities. A study of a free school meal program in the United States found that providing free meals to elementary and middle school children in areas characterized by high food insecurity led to increased school discipline among the students.
Childhood obesity is defined as a body mass index (BMI) at or above the 96th percentile for children of the same age and sex. It can cause a variety of health problems, including high blood pressure, high cholesterol, heart disease, diabetes, breathing problems, sleeping problems, and joint problems later in life. Children who are obese are at a greater risk for social and psychological problems as well, such as peer victimization, increased levels of aggression, and low self-esteem. Many environmental and social factors have been shown to correlate with childhood obesity, and researchers are attempting to use this knowledge to help prevent and treat the condition. When implemented early, certain forms of behavioral and psychological treatment can help children regain and/or maintain a healthy weight.
Obesity and the environment aims to look at the different environmental factors that researchers worldwide have determined cause and perpetuate obesity. Obesity is a condition in which a person's weight is higher than what is considered healthy for their height, and is the leading cause of preventable death worldwide. Obesity can result from several factors such as poor nutritional choices, overeating, genetics, culture, and metabolism. Many diseases and health complications are associated with obesity. Worldwide, the rates of obesity have nearly tripled since 1975, leading health professionals to label the condition as a modern epidemic in most parts of the world. Current worldwide population estimates of obese adults are near 13%; overweight adults total approximately 39%.
Nutrition is the intake of food, considered in relation to the body's dietary needs. Well-maintained nutrition includes a balanced diet as well as a regular exercise routine. Nutrition is an essential aspect of everyday life as it aids in supporting mental as well as physical body functioning. The National Health and Medical Research Council determines the Dietary Guidelines within Australia and it requires children to consume an adequate amount of food from each of the five food groups, which includes fruit, vegetables, meat and poultry, whole grains as well as dairy products. Nutrition is especially important for developing children as it influences every aspect of their growth and development. Nutrition allows children to maintain a stable BMI, reduces the risks of developing obesity, anemia and diabetes as well as minimises child susceptibility to mineral and vitamin deficiencies.
Obesity is defined as the excessive accumulation of fat and is predominantly caused when there is an energy imbalance between calorie consumption and calorie expenditure. Childhood obesity is becoming an increasing concern worldwide, and Australia alone recognizes that 1 in 4 children are either overweight or obese.
{{cite journal}}: CS1 maint: multiple names: authors list (link)