Obesity of 9,000 US adults: DEXA said 72% were obese, BMI said 42% were obese – June 2023

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MDEdge – BMI ‘vastly underestimates’ true obesity

Chat-GPT comparison of BMI and DEXA

Body Mass Index (BMI):
BMI is the most widely used method to assess obesity and overweight status in both adults and children due to its simplicity. It's a calculation based on a person's weight and height (BMI = kg/m2).

Pros of BMI:
Simple and quick: It only requires knowledge of a person's height and weight.
Widely accepted: Most studies and clinical settings use BMI to define obesity, making it easy to compare results across different populations and studies.

Cons of BMI:
Not direct: BMI doesn't directly measure body fat. It's possible for a muscular individual to have a high BMI but low body fat percentage.
No regional fat distribution: BMI cannot tell us about the distribution of fat within the body. This is important because visceral fat (around the organs) is more strongly linked to health risks than subcutaneous fat (under the skin).

Dual-Energy X-ray Absorptiometry (DEXA):
DEXA is a more advanced method that can directly measure body composition, including bone, fat, and muscle mass.

Pros of DEXA:
Direct measurement: DEXA provides a direct and accurate measurement of body fat percentage.
Regional fat distribution: DEXA can differentiate between different types of body tissue, and thus can give information about the distribution of fat and muscle within the body.

Cons of DEXA:
Complexity: DEXA requires special equipment and trained professionals, making it less accessible and more expensive than BMI.
Radiation exposure: Although the amount of radiation from a DEXA scan is quite low, it's still a factor to consider.

Overall, while BMI is a practical tool for initial screening and population-level studies, it has its limitations. DEXA provides more accurate and comprehensive data about body composition, but its use is often limited to research settings or specific clinical circumstances due to its higher cost and complexity.

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GPT comparing DEXA amd Body Impedance

Dual-Energy X-ray Absorptiometry (DEXA):
DEXA is a more advanced method that directly measures body composition, including bone, fat, and muscle mass.

Pros of DEXA:
Direct and accurate measurement: DEXA provides a direct and accurate measurement of body fat percentage.
Regional fat distribution: DEXA can differentiate between different types of body tissue, and thus can give information about the distribution of fat and muscle within the body.

Cons of DEXA:
Complexity: DEXA requires special equipment and trained professionals, making it less accessible and more expensive than other methods.
Radiation exposure: Although the amount of radiation from a DEXA scan is quite low, it's still a factor to consider.
Bioelectrical Impedance Analysis (BIA):
BIA estimates body composition by sending a small electrical current through the body and measuring the resistance to this current. The principle is that different tissues (fat, muscle, bone) conduct electricity differently.

Pros of BIA:
Simplicity and speed: BIA is a relatively simple, quick, and non-invasive method to estimate body composition.
Accessibility: BIA scales and handheld devices can be used at home, in a fitness setting, or in a clinical setting.

Cons of BIA:
Accuracy: The accuracy of BIA can be affected by many factors, including hydration status, food intake, skin temperature, and recent physical activity. Therefore, it's less accurate than DEXA.
Less detailed information: BIA does not provide as detailed information about the distribution of fat and muscle within the body as DEXA.

In conclusion, while DEXA provides more accurate and detailed information about body composition, its use is often limited to research settings or specific clinical circumstances due to its higher cost, complexity, and radiation exposure. On the other hand, BIA is a practical tool for estimating body composition in many settings, but its accuracy can be affected by various factors and it provides less detailed information compared to DEXA.

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Comparision of Body Fat Measures - 2004

Body composition changes in bodybuilders: a method comparison

BMI, body mass index;
SF, skinfolds;
BIA, bioimpedance;
DXA, dual x-ray absorptiometry;
dil, dilution by deuterium;
uww, underwater weighing;
3Cw, three-component model with body water;
3Cb, three-component model with body minerals.
 Download the PDF from VitaminDWiki

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100's of body weight scales on Amazon also measure body impedance - as low as $10

Amazon

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Comparison of measurement of Body Composition

MySportScience

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VitaminDWiki – Overview Obesity and Vitamin D contains

• FACT: People who are obese have less vitamin D in their blood
• FACT: Obese need a higher dose of vitamin D to get to the same level of vit D
• FACT: When obese people lose weight the vitamin D level in their blood increases
• FACT: Adding Calcium, perhaps in the form of fortified milk, often reduces weight
• FACT: 168 trials for vitamin D intervention of obesity as of Dec 2021
• FACT: Less weight gain by senior women with > 30 ng of vitamin D
• FACT: Dieters lost additional 5 lbs if vitamin D supplementation got them above 32 ng - RCT
• FACT: Obese lost 3X more weight by adding $10 of Vitamin D
• FACT: Those with darker skins were more likely to be obese Sept 2014
• OBSERVATION: Low Vitamin D while pregnancy ==> more obese child and adult
• OBSERVATION: Many mammals had evolved to add fat and vitamin D in the autumn
  • and lose both in the Spring - unfortunately humans have forgotten to lose the fat in the Spring
• SPECULATION: Low vitamin D might be one of the causes of obesity – several studies
• SUGGESTION: Probably need more than 4,000 IU to lose weight if very low on vitamin D due to
    risk factors such as overweight, age, dark skin, live far from equator,shut-in, etc.
• Obesity category has 442 items

See also: Weight loss and Vitamin D - many studies   Child Obesity and Vitamin D - many studies   Obesity, Virus, and Vitamin D - many studies
Obese need more Vitamin D

• Normal weight     Obese     (50 ng = 125 nanomole)

Click here for 2014 study

• Normal weight     Obese     (50 ng = 125 nanomole)

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VitaminDWiki – Obesity is associated and treated by Vitamin D

Fast weight loss by Obese Adults: Summary of the data as of Sept 2019
1) 50,000 IU Vitamin D weekly for at least 6 months
   If gut problems, should use a gut-friendly form of vitamin D
2) Add calorie restriction diet and light exercise after ~2 months*
   * Vitamin D levels must be above 30ng/ml to help with weight loss
   * Start losing weight 2 months sooner if take a 50,000 IU daily for a week
3) More weight loss if also add Magnesium or cofactors
   30% Improved Vitamin D response with Magnesium - a Vitamin D Cofactor
   Note: Magnesium reduces weight loss by itself as well
   20% improved vitamin D response if also add Omega-3 a Vitamin D Cofactor
  Note: Omega-3 reduces weight loss by itself as well
4) More weight loss if also improve activation of Vitamin D Receptor
   Vitamin D Receptor activator: 0-30% improved Vitamin D response
   Obesity 1.5 X more likely if poor Vitamin D Receptor – meta-analysis Nov 2019
Update Dec 2019 - Dr. Greger plant-based eating (not diet) for both weight loss and health.
  His book does not mention Vitamin D nor Adenovirus

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33+ VitaminDWiki pages with BMI in the title

This list is automatically updated

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67+ VitaminDWiki Obesity pages with WEIGHT in the title

This list is automatically updated