Flashcards in Over-nutrition and Disease Deck (29)
Obesity is classified according to BMI, quick review what are the classifications and associated co-morbidities?
1. Less than 18.5 - underweight --increased co-morbidity
2. 18.5 to 24.9 Normal --- average co-morbidity
3. 25.0 to 29.9 Overweight --- increased co-morbidity
4. Over 30 grade 2 obese --- moderate to severe co-morbidity
5. Over 40 grade 3 morbidity obese
Obesity can also be classified according to waist circumference. What are the measurements for increased risk?
Men: greater than 94cm (37inches) = increased risk and greater than 102cm (40inches) = substantially increased risk
Women: greaten than 80cm (31inches) = increased risk and greater than 88cm (35inches) = substantially increased risk
The prevalence of obesity is increasing rapidly in the US and worldwide. Rates are higher in what demographic of people?
Men or women tend to have higher BMIs?
In children (2-5), the percent obesity has increased from 5% in 71-74 to what percent in 03-04?
In developing world like Ghana there is an increase in obesity but....?
there is still a lot of malnutrition in these countries too (high monitary drain)
Overweight occurs concurrently with underweight in developing countries which diverts limited health resources and perpetuates what?
The prevalence does appear to be stabilizing, prevalence hasn't increased in men since 2003 or in women since 1999. However in children, what is happening to the rates?
Rates are still increasing in families with low SES and decreasing in those with high SES
(the poorer you are the fatter you are)
So what is the etiology of obesity?
1. It is a complex and multifactorial system
2. The social and built environment combine to form a obesogenic environment (encourages obesogenic behaviors like fast foods, large portion size and sedentary lifestyles)
This obesogenic environment fosters obesogenic behaviors, which when combined with a biological predisposition contributes to what?
A positive energy balance (nitrogen intake is greater than nitrogen expenditure) and weight gain
The changing social and physical environment encourage what?
consumption and discourage expenditure (both behaviors are incompatible with our genome)
Healthy foods such as fruits and veggies are getting more expensive while foods full of ________ are getting cheaper
High Fructose Corn Syrup (HFCS)
What evidence shows that increased portion size is contributing to obesity?
1. Restaurant meals are 38% larger than home cooked meals
2.Number of restaurants in the US have increased
3. Food from fast food restaurants is often very cheap and available in large quantities
4. Frequency of eating out at fast food restaurants is associated with an increase in energy and fat intake with a higher BMI
Obese people have higher BMR due to being heavier, why?
1. Expend more energy to perform the same amount of movement as lighter people but obese individuals move less overall
2. Sedentary behavior predicts increasing body fat sloth.
Based on studies done in the UK, energy intakes and obesity has shown what trends?
Energy intakes have fallen between 20 to 30%, suggesting even greater falls in physical activity
Obesity has developed within a move less eat somewhat less but still too much scenario
The obesity epidemic is likely due to what?
A changing social and physical environment that encourages consumption and discourages expenditures of energy, behaviors that are poorly compatible with the genome that we have inherited.
Is obesity the result of impaired metabolism or generalized inactivity?
---in the obese, metabolic rates are higher and energy spent on physical activity is the same as non-obese counterparts (lower movement is offset by the increased energy it takes to move larger body parts)
Is the obesogenic behavior due to increased nitrogen intake or decreased nitrogen expenditures?
--Most likely related to both factors
--It is typical to gain weight as you age, about 10kg over a 50 yr period (small imbalance but important)
Do our genetics have anything to do with our weight?
We have the same genes as our ancient ancestors, but a vastly different environment = our geneotypes really haven't changed since hunter gather periods.
--example of recent changes: maintained of the lactase enzyme and change in skin color
Our obesogenic behavior is poorly compatible with the genome that we have inherited. With how many genes strongly related to obesity?
12 genes (24 alleles) related to obesity
---BMI increases with obesity-susceptibility genetic variants
These SNPS (single nucelotide polymorphisms in 12 genes) has shown what in terms of BMI and weight?
BMI: 1.65 kg/m2
What is the best way to manage obesity?
Eat less + do more = weight loss
--physical activity provides the best scope for improvement
In the UK it was shown that what percent of adults are sedentary?
---the energy consumption has gone down since the 50s but there still isn't enough physical activity
In the UK it was shown that watching TV has what affect on obesity?
watching tv for greater than 3 hours a day doubles the risk of obesity
How does human behavior factor in to the equation of obesity?
1. Eating is essential, but exercise is not
2. The drive to eat is strong, but weak for exercise
3. The cessation signal to stop eating is weak, but strong to stop exercising
4. All the above factors are biased towards overeating and underactivity
Negative beliefs about exercise perpetuate the behavior of obesity. what is the negative belief?
Exercise increases hunger and food intake
--however studies show exercise does not induce automatic hunger and being sedentary does not diminish the drive to eat
One hour of moderate exercise can burn about how much kcal?
--men burn more calories than women for the same amount of exercise
What are the four approaches to the management of obesity??
1. Special Diets: slimming clubs, meal replacements and carb exclusion (Atkins and South Beach); Protein is highly satiating so it is an effective way to reduce intake; Fruits and Veggies need to be maintained; Quality of fat needs to be appropriate
2. Lifestyle Clinics: holistic approach to improve overall health
3. Cognitive behavioral therapy