Obesity 1: What is it and what are the impacts?

Obesity is a term given to someone with an excessive amount of body fat. There is a lot of stigma around this term in the medical field however, I will be referring to obesity as a disease. Obesity is not only an external issue but it causes havoc inside the body as well. In this blog, I will deep dive into the reason why people become obese and the impact this can have on your health. 

Metabolism

When we eat and digest food and drinks, our body converts these nutrients into energy. This is known as metabolizing. The idea of metabolism is that the amount of energy we consume (energy in / calories) minus the amount of energy we expend (energy out / exercise) equals energy stored (fat). This formula is controlled by our conscious mind and while it is somewhat true, it is too simplistic. 

Negative Feedback

There is also another process at work during metabolism called negative feedback which aims to maintain a stable internal environment in your body. This means that our body understands what we need to survive and will send signals to your brain to control your behaviour (ie. to stop eating). This is controlled by the subconscious mind, therefore, we have little control over this. This subconscious drive is directed by many factors which we will touch on in part two. 

The outdated rhetoric of ‘energy in’ vs ‘energy out’ is a concept that has been disproven time and time again in both research and first-person analogues relating to obesity. We will look closer at the influence of many factors including genetics, epigenetics, environment, geography and how economics can affect the food we eat and how our body responds to these foods. 

Obesity is defined by a term known as Body Mass Index (BMI). BMI is a tool used to understand how their weight is proportionally to their height. It is calculated using the calculation weight in kg divided by height in meters squared (kg/ m2). 

Defining your BMI

Weight Status	BMI
Underweight	Below 18.5
‘Normal’	18.5-24.9
Overweight	25-29.9
Obese	30 and higher

Unfortunately, there are some caveats to this method of labelling an individual's weight status. For example, generally, Asians have a much lower BMI due to their genetic makeup. It is estimated, that Asians with a BMI of 23 or over are at risk of increased health problems.

Additionally, these measurements do not take muscle mass into account. This can increase an individual's weight in kg but not affect their fat storage content. Therefore, highly muscular individuals may have a higher BMI than the health risks they involve. Additional measurements can be taken to negate these issues such as waist circumference (upwards 102cm in men and 89cm in women are associated with health risks) and body fat percentages. Together, these measurements give a much more accurate representation of a person’s risk of obesity and the risks that are involved with this condition. 

The Stats

Source: WHO (1 March 2024)(1)

• 1 in 8 people in the world are living with obesity

• In 2022, 43% of adults were overweight. About 16% of these are obese. 

• In 1990, 25% of adults were overweight. 

• In 2019, 5 million deaths were attributed to non-communicable diseases, in which, obesity plays a major role in the onset. (2)

What are the health impacts?

Being overweight or obese causes an abundance of health issues. Many of these issues cannot be overtly seen and are called non-communicable diseases. These diseases include: 

• Heart disease

• Stroke 

• Diabetes 

• Cardiovascular disorders 

• Digestive disorders

  
  

While obesity was often seen as an issue of high-income countries, it has become apparent that middle- and low- income countries are seeing a rise in obesity levels. This has led to what is called the ‘double- burden’ of malnutrition. This population is carrying excessive weight which is coexisting with malnutrition. The populations are eating low-nutrient food, generally high in saturated fats and sugars which are calorie dense and cause weight gain. These foods also fail to meet vitamin and mineral requirements causing further health consequences such as deteriorating bone health and deficiencies.  

Economic impacts

Not only does obesity have a huge impact on the health of the population, the cost of this disease to society is enormous. It is predicted that the economic impact of obesity will reach $3 trillion US dollars by 2030. While it is difficult to manage, the aim would be to prevent obesity in the population before it reaches treatment stages. 

Prevention and Management

In simple terms, obesity occurs when an individual is consuming too many calories and they are not burning off enough through exercise. Therefore, ‘energy-in’ vs ‘energy-out’ is out of balance. When the body is not burning the calories that we give it, it stores these extra calories as fat or carbohydrates. This is an evolutionary concept as our ancestors stored food with the logic that they were never sure when their next meal would arrive. However, with an abundance of food available to us at all time in first-world countries, this is not necessary anymore. 

Weight management strategies are usually delivered in primary care settings and are developed using this knowledge of how people store and lose weight. Many weight loss plans see individuals lose weight and keep this weight off for 12 months post-intervention, however, the weightloss is generally modest (approx -2.5kg over 12 months) (4, 5, 6). Nonetheless, this is a low cost, prevention strategy which has proven effects. It was found that patients trials where the patients had more interactions with their primary health practitioner, saw greater results. This outlines the importance of support during weight loss for more emotional, physical and mental backing. 

However, we have seen time and time again that these weight management strategies are not effective for everyone. Sometimes it can be more complicated than this simple rhetoric and there are many reasons why this could be the case. 

Part two will give you an insight into these intricacies.

References

1. https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight

2. GBD 2019 Risk Factor Collaborators. “Global Burden of 87 Risk Factors in 204 Countries and Territories, 1990–2019: a systematic analysis for the global burden of disease study 2019”. Lancet. 2020;396:1223–1249.

3. https://iris.who.int/bitstream/handle/10665/367784/9789240073234-eng.pdf?sequence=1

4. Ahern AL, Wheeler GM, Aveyard P, et al. Extended and standard duration weight-loss programme referrals for adults in primary care (WRAP): a randomised controlled trial. Lancet 2017;389:2214-25. doi:10.1016/S0140-6736(17)30647-5

5.  LeBlanc ES, Patnode CD, Webber EM, Redmond N, Rushkin M, O’Connor EA. Behavioral and Pharmacotherapy Weight Loss Interventions to Prevent Obesity-Related Morbidity and Mortality in Adults: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force. JAMA 2018;320:1172-91. doi:10.1001/jama.2018.7777

6. Madigan C D, Graham H E, Sturgiss E, Kettle V E, Gokal K, Biddle G et al. Effectiveness of weight management interventions for adults delivered in primary care: systematic review and meta-analysis of randomised controlled trials BMJ 2022; 377 :e069719 doi:10.1136/bmj-2021-069719