The relationship between healthy eating and climate change remains elusive?
Human obesities represent a complex medical disorder of multiple origin. Genetic predisposition, diverse health behaviors, and individual food choices all contribute in varying degrees. Influenced by familial risk and modulated by changes in energy intake, physical activity, and energy expenditure. Why change a lifestyle to vegetarianism?
- Nearly 70% of American adults are classified as overweight/obese 
- Adults age 20 years and over with obesity: 37.9% (2013-2014)
- Adults age 20 years and over with overweight, including obesity: 70.7% (2013-2014)
- An estimated 108 million Americans are on a diet.
Clearly, our collective approach to nutritional health isn’t working.
Healthful and unhealthful eating patterns are learned at an early age. Although, there's been many years of scientific research 7 out of 10 American adults aged 20 and over remain overweight. So, why aren't American low-fat diets working?
One factor is the consumption of high Glycemic Index, GI, carbohydrates. Weight gain is not solely the result of storing the fats in our meals. Insulin affects surplus glucose resulting from excessive consumption of high GI carbohydrates. For many years, nutritionists believed that glucose could not be converted into fat. This is why they recommended diets rich in carbohydrates pretending that they did not make people gain weight.
By advising people to eliminate fats from their diets and recommending they eat carbohydrates, some nutritionists contributed to the spreading of obesity. Failure to advise their patients on which carbs to eat left people eating high-GI carbs. This made their bodies secrete additional insulin and generate greater amounts of surplus glucose which their bodies did not need and stored as fat. Additional information on food GI and it's impact on our weight can be found - Impact of Glycemic Index.
It's estimated that 75% of all diseases could be prevented with better nutrition and 97% of women confess they have at least one "I hate my body moment" each day! 
Vegetarianism and the psychology of eating
Nutrition alone is not adequate to address the compelling challenges we face with food, weight, body image, and overeating... Instead, we must fully embrace the psychology of the eater – the heart, mind and soul of what it means to nourish one’s body and being. From there, true healing is possible. Marc David 
The leading cause of death of both men and women in the United States is heart disease. Every day, nearly 2,600 Americans die of some type of heart disease, the most common form being coronary heart disease, also known as atherosclerosis. Atherosclerosis occurs when hard layers of plaque, usually cholesterol deposits, accumulate in major arteries and begin constricting flow of blood and oxygen to the heart. Arterial plaque is also a leading cause of stroke, the fourth greatest killer of Americans each year. 
While other factors can affect cholesterol levels and heart disease (including smoking, exercise, blood pressure, and body weight) one of the single most significant causes of heart disease is dietary cholesterol. Our bodies make all the cholesterol we need, so consuming animal products contributes excessive levels. (There is no cholesterol in plant foods). Animal products are also loaded with saturated fats, which, unlike unsaturated fats, cause the liver to produce more cholesterol. 
Fortunately, for most people, preventing coronary heart disease is as simple as eating a plant-based diet, exercising, and avoiding smoking. But beyond prevention, a plant-based diet is the only treatment that has been scientifically proven to reverse heart disease.
Researchers assessed four different scenarios with humans consuming varying levels of meat. The lowest level of meat consumption—widespread adoption of the vegan diet—could help avoid more than 8 million deaths by 2050, according to the study. 
The environmental impacts of a dietary shift towards vegetarianism are just as dramatic, according to researchers. Changing dietary patterns could save $1 trillion annually by preventing health care costs and lost productivity. That figure balloons to as much as $30 trillion annually when also considering the economic value of lost life. And that doesn't include the economic benefits of avoiding devastating extreme weather events that could result from climate change. 
Animal Agriculture - Significant Climate Change Impact 
- 70% of crops grown are fed to livestock, which produce large amounts of waste and methane - a heat-trapping gas more than 25 times more potent than carbon dioxide.
- Animal agriculture is responsible for 18 percent of greenhouse gas emissions, more than the combined exhaust from all transportation.
- The leading cause of rainforest destruction, Animal Agriculture is responsible for ~91% of Amazon destruction.
- Collateral damage - Scientists estimate as many as 650,000 whales, dolphins and seals are killed every year by fishing vessels.
- 82% of starving children live in countries where food is fed to animals, and the animals eaten by western countries.
- To your Health - 80% of antibiotic sold in the US are for livestock.
Resources Needed to Make a Quarter-Pound Hamburger
A person who follows a vegan diet produces the equivalent of 50% less carbon dioxide, uses 1/11th oil, 1/13th water, and 1/18th land compared to a meat-lover for their food. Each day, a person who eats a vegan diet saves 1,100 gallons of water, 45 pounds of grain, 30 sq ft of forested land, 20 lbs CO2 equivalent, and one animal’s life.
Fortunately, albeit slowly, the global trend moves towards plant-based diets. Are there more reasons than taste influencing our decision to eat other animals? Westerners are raised with the ability to obtain an infinite supply of animal products at the supermarket that include: cow, chicken, pork, and fish. Strangely, there are also many animals not acceptable, such as dogs & cats. Cannibalism remains forbidden in western societies although the Christian symbolic reference to eating the body and blood of Christ remains present during Sunday Mass. Which animal products are ok?
Peter Singer (Princeton University and University of Melbourne professor and pioneer of the animal liberation movement) has long argued that, if it is possible to survive and be healthy without eating meat, fish, dairy, or eggs, one ought to choose that option instead of causing unnecessary harm to animals. In Animal Liberation, Singer argued that, because non-human animals feel, they should be treated according to utilitarian ethics. Singer's work has since been widely built upon by philosophers, both those who agree and those who do not, and it has been applied by animal rights advocates as well as by ethical vegetarians and vegans.
Ethical vegetarians say that the reasons for not hurting or killing animals are similar to the reasons for not hurting or killing humans. They argue that killing an animal, like killing a human, can only be justified in extreme circumstances; consuming a living creature for its taste, for convenience, or out of habit is not justifiable. Some have added that humans, unlike other animals, are morally conscious of their behavior and have a choice; this is why there are laws governing human behavior, and why it is subject to moral standards.
"The least I can do is speak for those who cannot speak for themselves" - Jane Goodal
The animals we eat are in fact living animals who want to live, love life and fear death. Witnessing humane video of animals in line to be slaughtered will attest to this fact.
Someday, we may look back at our behavior during this period as anthropophaginian considering equal treatment of animals. I can only hope that if intelligent life visits from another world, that they've evolved past the point of wanting to taste us, albeit potentially tasty intelligent beings!
As we continue our forward journey what will become of our dining ritual? Maybe we will begin to focus on self-preservation of ourselves with the planet and revise our focus towards proper nourishment of the mind, body and soul?