Approximately 2 billion people globally are either obese or overweight and have a higher risk of chronic diseases.
High consumption of meat, dairy and energy-dense foods are linked to obesity[1,3,5].
Obesity can be defined as abnormal or excessive fat accumulation in the body and can be a hindrance to perfect health. World health organization (WHO) considers obesity as one of the five leading risk factors for death related to non-communicable diseases.
Body Mass Index (BMI), a universal index used to classify obesity and overweight is a simple ratio of a person body’s weight to his/her height in sq. metres.
A person with BMI ratio greater than or equal to 25 is considered obese and a ratio greater than or equal to 30 is considered overweight .
WHO states that obesity has tripled between 1975 and 2016 .
Quick Stats About Obesity – 2016 Data.
Million Children are Obese
Million Adults are Obese
Billion Adults are Overweight
Obesity in children is a massive concern. Researchers estimate that an obese child is much more likely to be an obese adult.
They are also at a higher risk of disability in adulthood, breathing difficulties, hypertension and even premature death.
The map below map shows the percentage of adults per country who are defined as obese.
Source: World Health Observatory & Our World in Data (2016)
Interestingly, most of the countries with the highest percentage of obesity population are also the biggest meat-eating countries.
Average total meat supply per person measured in kilograms per year
Source: World Health Observatory & Our World in Data (2013)
On the other hand, multiple studies have pointed out that vegans tend to have a lower BMI as compared to vegetarians or non-vegetarians. They are also more likely of losing weight by eating plant proteins which is low on fatty acids[3,6,7].
Chronic Diseases Risk Due To Obesity
Raised BMI or being obese increases the risk of major non-communicable diseases like cardiovascular heart diseases, cancer and diabetes [1,2].
World Health Organization claims that obesity is no longer a problem only in high-income countries but also spreading rapidly in low and middle-income countries, particularly in urban settings.
Cancer And Obesity
According to the International Agency for Cancer Research (IARC), being obese or overweight increases the risk of 12 different types of cancer.
Source: International Agency for Cancer Research
More importantly, having abdominal fat can do more damage than just being obese. As per Cancer Research UK, excess body fat can cause insulin and growth factors levels in the body to rise which in turn gives signals to the cells to divide more often, thereby increasing the possibility of cancer.
Source: Cancer Research UK
Cardiovascular Diseases (CVD) And Obesity
Global Atlas report on Cardiovascular diseases from WHO states that there is a strong correlation between obesity and major cardiovascular risk factors such as raised blood pressure, glucose intolerance, type 2 diabetes and dyslipidaemia .
Scientists have repeatedly claimed that obese people tend to have higher levels of LDL cholesterols, and lower levels of HDL cholesterol and fasting plasma triglycerides in their bloodstream which are known to be a cause for arteries getting blocked .
Diabetes And Obesity
Obesity is the strongest risk factor for Type-2 diabetes, and it is estimated that 90% of diabetic people are either obese or overweight .
Higher waist circumference and higher body mass index have a strong relationship with diabetes and insulin resistance .
As per research, abdominal obesity causes fat cells to release inflammatory mediators that can lead to insulin resistance, impaired glucose levels and eventually diabetes .
Insulin sensitivity is also affected when fat molecules are released into the blood due to change in the body’s metabolism .
Although obesity and weight gain can worsen insulin resistance, medical experts also believe that weight loss slows the progression of diabetes complications .
Causes of Obesity
WHO states that an energy imbalance between calories consumed and calories expended is the fundamental cause of obesity and overweight .
Increased intake of energy-dense foods that are high in fat and glycaemic index as well as physical inactivity can lead to energy imbalance [1,5].
Saturated fatty acids found in food from animal sources like meat, butter, milk, cheese, ghee, salmon and egg yolk can elevate bad cholesterol levels in the body and significantly increase hip to waist ratio [22,12].
Multiple studies have linked a positive association of high meat consumption to obesity, higher Body Mass Index and waist circumference[7,12].
China, for example, has witnessed a massive growth in the past few decades. However, with the increasing income, chinese meat consumption has more than doubled between 1993 and 2006 .
A study done over a period of 2 decades with more 16,000 participants found a strong co-relation between meat consumption and obesity, especially abdominal obesity .
Similarly, trans-fatty acids found naturally in ruminant animals like cattle, sheep, goats, camels, etc and in industrially processed partially hydrogenated oil can also have a negative effect on the cholesterol levels .
Dalda, a type of vegetable ghee or clarified butter and a major source of edible oil in India, has a trans-fat level of about 50% and has been attributed as a major cause for rising obesity levels in India in spite of low meat consumption .
Excessive Animal Protein
A diet that is low in carbs and high in animal protein (Atkins diet) has been recommended for weight loss, but researchers have questioned the long-term gains of these diets [8,9,10].
Clinical studies have concluded that although many people claimed losing weight initially following the above diet, eventually did put on weight after following the same diet for more than 6 months [7,10].
Recent research conducted after collating data from 170 countries found out red meat and obesity are closely related. It is believed that when excess animal protein is consumed (i.e. more than 25% of the total calorie intake), due to its slower digestion rate it is converted and stored as fats and the person has a 23% higher risk of becoming overweight(6,7,10).
Furthermore, a study done in the UK found that even chicken, considered to be a leaner protein source, provide more fat-energy than protein-energy.
Frequent consumption of high energy foods, such as processed foods, refined carbohydrates and sugary drinks that are high in fats and sugars promotes obesity .
Foods high on the glycaemic index and glycemic load like white rice, potatoes, white pasta etc. have also been linked to a higher waist-to-hip ratio and Body mass index.
Reducing Risks of Obesity
Limiting total energy intake from fats and sugars, increasing fruits and vegetable intakes and being physically active are some of the recommendation by industry experts to prevent obesity.
Increase Fruits And Veggies Intake
Fruits and vegetables can help against weight gains on several fronts: –
They are rich in micro-nutrients i.e. Potassium, magnesium and calcium have all proven to be beneficial for weight loss . They have low energy density and are high in water and fibre content which affects satiety [14,15].
Plant sterols present in fruits and veggies can interfere with fat absorption and thereby prevent weight gain .
Polyphenols, one of the beneficial compounds, in these foods can prevent weight gain through their antioxidant and anti-inflammatory properties by increasing energy expenditure and production of heat.
Eat Quality Carbs And Fibre-Rich Foods
Non-starchy vegetables and fruits may prevent weight gain as their low glycemic loads could prevent blood sugar spikes which are responsible for increasing hunger .
When it comes to carbohydrates, scientific studies have repeatedly emphasized that quality is more important than the quantity when it comes to weight loss[5,14,15].
That necessarily means replacing high carbs and refined grain foods like potato, sugary drinks, white rice, white bread with complex carbs like whole grains bread, brown rice, legumes, pulses etc which can digest easily and release energy slowly.
These foods, rich in fibre and low in saturated fats can also slow digestion thereby helping to curb hunger. Studies have shown that consuming at least 20 grams of fibre/ day can prevent weight gain [15,16].
Increase Consumption Of Plant Protein
As per recent reports, unlike animal protein, eating a diet high in plant protein can help reduce weight gain [10,7,17].
Plant and animal protein have different effects on body weights as plant protein varies in its digestibility due to its amino acid concentrations and may provide considerably less energy as compared to animal protein .
Evidence shows that plant protein, especially soy protein, can stimulate lipid metabolism resulting in lower bad cholesterol levels, triglycerides and insulin resistance .
Being Physically Active
This one’s a no brainer but still deserves a mention due to its significance. Obesity results, when there is an imbalance between energy intake in the diet and energy expenditure. Regular physical activity can prevent obesity by increasing the expended energy.
WHO suggests engaging in at least physical activity 60 minutes a day for children and 150 minutes for adults a week . Even maintaining a healthy lifestyle and refraining from excess alcohol and smoking can help fight obesity .