How to lose weight by green tea naturally?

Green tea is the healthiest beverage on the planet.

It is loaded with antioxidants and various substances that are beneficial for health.

Many studies have shown that green tea can increase fat burning and help you lose weight.

Let me explain how that works…

Green Tea Contains Substances That Can Help You Lose Fat

Green tea is more than just hot, flavored water.

The bioactive substances in the tea leaves dissolve in the water and make it into the final drink.

When you drink a cup of quality tea, you’re actually getting a large amount of beneficial substances with potent biological effects.

The best known of these is caffeine. A cup of green tea contains much less caffeine (24-40 mg) than a cup of coffee (100-200 mg), but still enough to have a mild effect.

Caffeine is a well known stimulant that has been shown to aid fat burning and improve exercise performance in numerous studies.

But where green tea really shines is in its massive range of antioxidants… being loaded with potent antioxidants called catechins.

The most important of these is EGCG (Epigallocatechin gallate), a substance that can boost metabolism.

Keep in mind that these benefits can be derived both from drinking green tea as a beverage, as well as taking green tea extract as a supplement. Most of the studies used extracts.

Bottom Line: Green tea contains bioactive substances like caffeine and EGCG, which can have powerful effects on metabolism.

Green Tea Can Help Mobilize Fat from Fat Cells

In order to burn fat, it must first be broken down in the fat cell and moved into the bloodstream.

The active compounds in green tea can aid in this process by boosting the effects of some fat burning hormones.

The main antioxidant in tea, EGCG, can help inhibit an enzyme that breaks down the hormone norepinephrine.

When this enzyme is inhibited, the amount of norepinephrine increases.

This hormone is used by the nervous system as a signal to the fat cells, telling them to break down fat. Therefore, more norepinephrine leads to a stronger signal being sent to the fat cell and more fat gets broken down.

Caffeine and EGCG (both found naturally in green tea) may actually have a synergistic effect, because caffeine enhances another step in the same pathway.

The end result is that the fat cell breaks down more fat, which is released into the bloodstream and becomes available for use as energy by cells that need it, like muscle cells.

Bottom Line: The substances in green tea increase levels of hormones that tell fat cells to break down fat. This releases fat into the bloodstream and makes it available as energy.

Green Tea Increases Fat Burning, Especially During Exercise

If you look at the label of almost every commercial weight loss and fat burning supplement, chances are that you will find some kind of tea there as an ingredient.

This is because green tea has been repeatedly shown to increase the burning of fat, especially during exercise.

In one study, men who took green tea extract and exercised burned 17% more fat than men who didn’t get the supplement. This study suggests that green tea can boost the fat burning effects of exercise.

Another study that went on for 8 weeks showed that green tea increased fat burning, both during exercise and during rest.

There are several studies that agree with this. Green tea selectively boosts the burning of fat, which may lead to reduced body fat in the long term.

Bottom Line: A number of studies show that green tea extract can boost the burning of fat. The effect is even stronger when exercising.

Green Tea Can Boost the Metabolic Rate And Make You Burn More Calories Around The Clock

The human body is constantly burning calories.

Even when sleeping or sitting down, our cells are performing billions of functions that require energy.

Several studies suggest that green tea can make us burn more calories, even at rest.

In most studies, this amounts to about a 3-4% increase, although some studies show an increase as high as 8% .

For a person who burns 2000 calories per day, 3-4% amounts to an additional 60-80 calories per day, similar to what you might expect with a high protein diet.

Although most of the studies were very short in duration (1-3 days), there is also some evidence that the metabolism boosting effect persists in the long term.

In one study of 60 obese individuals, the group taking green tea extract lost 7.3 lbs (3.3 kg) and burned 183 more calories per day after 3 months.

However, keep in mind that not all studies show that green tea boosts metabolism. The effect may depend on the individual.

Bottom Line: Several studies show that green tea can boost metabolism and help people burn about 3-4% more calories each day.

Can Green Tea Make You Automatically Take In Fewer Calories?

One way that green tea could help with weight loss, is by reducing appetite.

This would make us take in fewer calories, automatically, without any effort.

Several studies have looked at the effects of green tea on appetite, but most showed conflicting results.

There are also animal studies suggesting that green tea can reduce the amount of fat we absorb from foods, but this has not been confirmed in humans.

Overall, it seems that green tea exerts its effects primarily by increasing “calories out”… it makes us burn more fat, but it doesn’t appear to have any noticeable effect on how much food we end up eating throughout the day.

Bottom Line: There is currently no evidence that green tea makes people eat fewer calories. Some studies in animals suggest that it may reduce the absorption of fat from the diet, but this has not been confirmed in humans.

Green Tea Can Help You Lose Fat, Especially The Harmful Abdominal Fat

When it comes to actual pounds losts, the effects of green tea are relatively modest.

Although there are numerous studies showing that people do in fact lose weight, there are also some studies showing no effect.

Two review studies that looked at many controlled trials found that people lost about 3 pounds (1.3-1.4 kg) on average.

However… it’s important to keep in mind that not all fat is the same.

We have subcutaneous fat that lodges under the skin, but then we also have visceral fat, which is the belly fat that builds up around the organs.

It is this deep visceral fat that is harmful. It causes inflammation and insulin resistance, both of which are strongly linked to all sorts of serious diseases, including type 2 diabetes and heart disease.

Several studies on green tea show that although the weight loss effects are modest, a significant percentage of the fat lost is the harmful visceral fat.

This should translate to a reduced risk of many killer diseases down the line… which may lead to a longer and healthier life.

Take Home Message

Even though green tea can mildly increase metabolism and fat burning, the effects are modest when it comes to actual pounds lost.

However, every little bit adds up and it may work even better when combined with other effective weight loss strategies like eating more protein and cutting carbs.

Of course… let’s not forget that green tea goes way beyond just body weight. It is also extremely healthy for various other reasons.

If you want to read more about the many impressive health benefits of green tea, then check out this article: Top 10 Evidence-Based Health Benefits of Green Tea.

By Kris Gunnars

How Weight Loss by Coconut oil ?

Coconut oil is the world’s most weight loss friendly fat.

It contains a unique combination of fatty acids with powerful effects on metabolism.

Several studies show that just by adding coconut oil to your diet, you can lose fat, especially the “dangerous” fat in the abdominal cavity.

Let me explain how that works…

Coconut Oil is High in Medium Chain Triglycerides, Fatty Acids That Boost Metabolism

Coconut oil is vastly different from most other fats in the diet.

Whereas most foods contain predominantly long-chain fatty acids, coconut oil consists almost entirely of Medium Chain Fatty Acids.

The thing with these medium chain fatty acids, is that they are metabolized differently than the longer chain fats.

They are sent straight to the liver from the digestive tract, where they are either used for energy right away or turned into ketone bodies.

These fats are often used by epileptic patients on a ketogenic diet, in order to increase ketone levels while allowing for a bit more carbs in the diet.

There is also some evidence from animal studies that medium chain fats are stored less efficiently than other fats.

In one study, rats were overfed with either long chain or medium chain fats. The rats fed the medium chain fats gained 20% less weight and 23% less body fat.

Bottom Line: Coconut oil is high in Medium Chain Triglycerides, which are fatty acids that are metabolized differently than most other fats, leading to beneficial effects on metabolism.

How Coconut Oil Can Boost Metabolism, Making You Burn More Calories at Rest

A calorie is not a calorie.

Different foods and macronutrients go through different metabolic pathways.

The different types of foods we eat can have a huge effect on our hormones and metabolic health.

Some metabolic pathways are more efficient than others and some foods require more energy to digest and metabolize.

One important property of coconut oil is that it is “thermogenic” – eating it tends to increase energy expenditure (fat burning) compared to the same amount of calories from other fats.

In one study, 15-30 grams (1 to 2 tablespoons) of medium chain fats per day increased energy expenditure by 5%, totaling about 120 calories per day.

Several other studies confirm these findings. When humans replace the fats they are eating with MCT fats, they burn more calories.

Therefore, a calorie from coconut oil is NOT the same as a calorie from olive oil or butter (although these fats are perfectly healthy too).

Bottom Line: Many studies show that medium chain triglycerides can boost metabolism, in one study increasing energy expenditure by 120 calories per day.

Coconut Oil Can Reduce Appetite, Making You Eat Less Without Trying

“Weight loss is all about calories in, calories out.”

Even though I think this is a drastic oversimplification, it is mostly true.

If your body expends more energy (calories) than it takes in, then you will lose fat.

But even though it is true that we need to be in a calorie deficit to lose weight, it doesn’t mean that calories are something that we need to count or be consciously aware of.

Humans are very capable of remaining lean and healthy in their natural environment. The obesity epidemic didn’t start until 1980 and we didn’t even know what a calorie was back in the day.

Anything that reduces our appetite can make us take in fewer calories without having to think about it. It appears that coconut oil has this effect.

Many studies on medium chain fatty acids show that, compared to the same amount of calories from other fats, they increase feelings of fullness and lead to an automatic reduction in calorie intake.

This may be related to the way these fats are metabolized. It is well known that ketone bodies (which the liver produces when you eat coconut oil) can have a powerful appetite reducing effect.

Whatever the mechanism is, it works. In one study of 6 healthy men, eating a high amount of MCTs caused them to automatically eat 256 fewer calories per day.

In another study of 14 healthy men, those who ate MCTs at breakfast ate significantly fewer calories at lunch.

So… coconut oil boosts fat burning (increases “calories out”) and it also reduces the appetite (reduces “calories in”).

Bottom Line: Many studies show that people who add Medium Chain Fatty Acids to their diet have reduced appetite and start eating fewer calories automatically.

Coconut Oil Can Help You Lose Fat, Especially The “Dangerous” Abdominal Fat

If coconut oil can boost metabolism and reduce appetite, then it should help you lose fat over the long term.

In fact, there are several studies that support this.

In one study, 40 women were given either 30 grams (2 tablespoons) of either coconut oil or soybean oil for 28 days.

They were instructed to eat fewer calories and walk every day. These were the results:

Both groups lost weight (about 2 pounds).

Only the coconut oil group had decreased waist circumference (belly fat) while the soybean oil actually had a mild increase in belly fat.

The coconut oil group had increased HDL (good) cholesterol levels, while the soybean oil had reduced HDL and increased LDL.

In this study, coconut oil did not cause overall weight loss compared to soybean oil, but it did lead to a significant reduction in belly fat.

In another study in obese men, 30 grams of coconut oil for 4 weeks reduced waist circumference by 2.86 cm, or 1.1 inches.

There are also other studies showing that medium chain fats lead to weight loss, reduced waist circumference and various improvements in metabolic health.

The weight loss effects of coconut oil appear to be fairly mild, except for the abdominal fat.

Abdominal fat, also called visceral fat or belly fat, is the fat that tends to lodge around your organs and cause inflammation, diabetes and heart disease.

Any reduction in abdominal fat is likely to have very positive effects on your metabolic health, longevity and drastically reduce your risk of chronic disease.

These results are far from being dramatic, but consider that all these people are doing is adding coconut oil to their diet.

Combined with other proven weight loss strategies (like cutting carbs and increasing protein), all of this can add up to a significant amount.

Therefore, coconut oil can support a healthy, real-food based weight loss diet, but don’t expect it to work any miracles on its own.

If you’re interested in even more research on coconut oil, then you can find a very impressive collection of studies here.

Bottom Line: Eating coconut is particularly effective at reducing the harmful belly fat in the abdominal cavity, which is strongly associated with disease.

What About The Calories?

It’s important to keep in mind that coconut oil is fat.

Fat has 9 calories per gram… and coconut oil is no exception.

Therefore, if you are eating a fixed amount of calories and then add coconut oil on top of that, then it’s likely to make you gain weight, not lose.

However, most people aren’t counting calories and eating a fixed amount per day.

In these cases, adding coconut oil to your diet will reduce your appetite and probably make you eat less of other foods instead.

So this really is not about adding fat calories to your diet, it is about replacing some of your other cooking fats with coconut oil.

It’s also important not to go overboard and think you need to add tons of coconut oil to your diet to reap the benefits. The studies above used about 30 grams per day, which equals 2 tablespoons.

Even if coconut oil is good for cooking and has some powerful health benefits, your diet should still consist primarily of whole, nutritious foods like plants and animals.

You can read more about the other amazing health benefits of coconut oil here.

By Kris Gunnars

How Many Carbs Should You Eat Per Day to Lose Weight?

Reducing the amount of carbohydrates in your diet is one of the best ways to lose weight.

It tends to reduce your appetite and cause “automatic” weight loss, without the need for calorie counting or portion control.

This means that you can eat until fullness, feel satisfied and still lose weight.

Why Would You Want to do Low-Carb?

For the past few decades, the health authorities have recommended that we eat a calorie restricted, low-fat diet.

The problem is that this diet doesn’t really work. 

Even when people manage to stick to it, they don’t see very good results.

An alternative that has been available for a long time is the low-carb diet.

 This diet restricts your intake of carbohydrates like sugars and starches (breads, pasta, etc.) and replaces them with protein and fat.

Studies show that low-carb diets reduce your appetite and make you eat less calories and lose weight pretty much effortlessly, as long as you manage to keep the carbs down.

In studies where low-carb and low-fat diets are compared, the researchers need to actively restrict calories in the low-fat groups to make the results comparable, but the low-carb groups still usually win.

Low-carb diets also have benefits that go way beyond just weight loss. 

They lower blood sugar, blood pressure and triglycerides. They raise HDL (the good) and improve the pattern of LDL (the bad) cholesterol.

Low-carb diets cause more weight loss and improve health much more than the calorie restricted, low-fat diet still recommended by the mainstream. This is pretty much a scientific fact at this point.

Bottom Line: There are many studies showing that low-carb diets are more effective and healthier than the low-fat diet that is still recommended all around the world.

How to Figure Out Your Need For Carbohydrates

There is no clear definition of exactly what constitutes a “low carb diet” and what is “low” for one person may not be “low” for the next.

An individual’s optimal carb intake depends on age, gender, body composition, activity levels, personal preference, food culture and current metabolic health.

People who are physically active and have more muscle mass can tolerate a lot more carbs than people who are sedentary.

This particularly applies for those who do a lot of high intensity, anaerobic work like lifting weights or sprinting.

Metabolic health is also a very important factor.

 When people get the metabolic syndrome, become obese or get type II diabetes, the rules change.

People who fall into this category can’t tolerate the same amount of carbs as those who are healthy. 

Some scientists even refer to these problems as “carbohydrate intolerance.”

Bottom Line: The optimal carb range varies between individuals, depending on activity levels, current metabolic health and a bunch of other factors.

Guidelines That Work 90% of The Time

If you simply remove the unhealthiest carb sources from your diet, wheat (including whole wheat) and added sugars, then you’ll be well on your way to improved health.

However, to enjoy the full metabolic benefits of low-carbohydrate diets, you also need to restrict other carb sources.

Even though there is no scientific paper that explains exactly how to match carbohydrate intake to individual needs, I have personally found these guidelines to be very effective.

100-150 Grams Per Day

This is more of a “moderate” carbohydrate intake. 

It is very appropriate for people who are lean, active and simply trying to stay healthy and maintain their weight.

It is very possible to lose weight at this (and any) carb intake, but it may require you to count calories and/or control portions.

Carbs you can eat:

• All the vegetables you can             imagine.
• Several pieces of fruit per day.
• Some amount (not a lot) of healthy starches like potatoes, sweet potatoes and healthier grains like rice and oats.

50-100 Grams Per Day

This range is great if you want to lose weight effortlessly while allowing for a bit of carbs in the diet.

 It is also a great maintenance range for people who are carb sensitive.

Carbs you can eat:

•  Plenty of vegetables.
•  Maybe 2-3 pieces of fruit per day.
•  Minimal amounts of starchy              carbohydrates.

20-50 Grams Per Day

This is where the metabolic benefits really start to kick in.

This is the perfect range for people who need to lose weight fast, or are metabolically deranged and have obesity or diabetes.

When eating less than 50 grams per day, your body will get into ketosis, supplying energy for the brain via so-called ketone bodies.

 This is likely to kill your appetite and cause you to lose weight automatically.

Carbs you can eat:

•  Plenty of low-carb vegetables.
•  Some berries, maybe with whipped        cream (yum).
•  Trace carbs from other foods like        avocados, nuts and seeds.

Be aware that a low-carb diet is NOT no-carb. There is room for plenty of low-carb vegetables (full list here).

 Personally I had never eaten as many veggies as when I first started on a low-carb diet.

Important to experiment

We are all unique and what works for one person may not for the next.

 It is important to do some self-experimentation and figure out what works for you.

If you have a medical condition then make sure to talk to your doctor before making any changes, because this diet can drastically reduce your need for medication!

Bottom Line: For people who are physically active or want to maintain their weight, a range of 100-150 grams per day may be optimal. For people who have metabolic problems, going under 50 grams per day is a good idea.

Good Carbs, Bad Carbs

Shocked Woman Eating Bread

A low-carb diet isn’t just about weight loss, it is also supposed to improve your health.

For this reason, it should be based on real, unprocessed foods and healthy carb sources.

So-called “low carb junk foods” are a bad choice.

If you want to improve your health, then choose unprocessed foods: meats, fish, eggs, vegetables, nuts, healthy fats and full-fat dairy products.

Choose carbohydrate sources that include fiber.

 If you prefer a “moderate” carb intake then try to choose unrefined starch sources like potatoes, sweet potatoes, oats, rice and other non-gluten grains.

Added sugar and wheat are always bad options and should be avoided, unless perhaps on special occasions.

For more details on specific foods to eat, check out this detailed low-carb meal plan and sample menu.

Bottom Line: It is very important to choose healthy, fiber-rich carb sources. There is room for plenty of vegetables, even at the lowest end of the carb range.

You Will Become a Fat Burning Beast

Low-carb diets greatly reduce your blood levels of insulin, a hormone that brings the glucose (from the carbs) into cells.

One of the functions of insulin is to store fat. Many experts believe that the reason low-carb diets work so well, is that they reduce your levels of this hormone.

Another thing that insulin does is to tell the kidneys to hoard sodium. This is the reason high-carb diets can cause excess water retention.

When you cut carbs, you reduce insulin and your kidneys start shedding excess water.

It is common for people to lose a lot of water weight in the first few days on a low-carb diet, up to 5-10 pounds.

Weight loss will slow down after the first week, but this time the fat will be coming from your fat stores.

One study compared low-carb and low-fat diets and used DEXA scanners (very accurate) to measure body composition.

The low-carb dieters lost significant amounts of body fat and gained muscle at the same time.

Studies also show that low-carb diets are particularly effective at reducing the fat in your abdominal cavity (belly fat), which is the most dangerous fat of all and highly associated with many diseases.

If you’re new to low-carb eating, you will probably need to go through an adaptation phase where your body is getting used to burning fat instead of carbs.

This is called the “low-carb flu” and is usually over within a few days.

 After this initial phase is over, many people report having more energy than before, with no “afternoon dips” in energy that are common on high-carb diets.

Adding more fat and sodium to your diet can help with this.

Bottom Line: It is common to feel suboptimal in the first few days of lowering your carb intake. However, most people feel excellent after this initial adaptation phase.

Take Home Message

If you want to try this out, then I recommend that you try tracking your food intake for a few days to get a “feel” for the amount of carbs you are eating.

My favorite app for this is called Cron-O-Meter. 

Because fiber grams don’t really count as carbohydrates, you can exclude the fiber grams from the total number. Instead, count net carbs (net carbs = total carbs – fiber).

However, one of the great benefits of low-carb diets is that they’re ridiculously simple. 

You don’t need to track anything if you don’t want to.

Just eat some protein, healthy fats and veggies at every meal. Throw in some nuts, seeds and full-fat dairy products for good measure.

 Choose unprocessed foods. It doesn’t get much simpler than that!

You can find more info on this page, including a meal plan, sample menu, recipes, common mistakes, etc: The Ultimate Guide to Low-Carbohydrate Diets.

By Kris Gunnars

12 Graphs That Show Why People Get Fat

People are fatter and sicker than ever before.
Obesity rates have tripled since 1980 and have increased particularly fast in children.
The reason why this has happened is still debated among scientists, but it must be due to changes in the environment because our genes don’t change this quickly.

This article contains graphs with historical trends and results from obesity studies, showing some of the main reasons why obesity has become such a massive problem.
Here are 12 graphs that show why people get fat.
1. People Are Eating More Junk Food Than Ever

Source: Dr. Stephan Guyenet. Fast Food, Weight Gain and Insulin Resistance. Whole Health Source
People are eating more calories than before… but pretty much all of the increase has come from processed foods.
In the graph above, you see how the population changed its eating habits in the past 120-130 years.
At the turn of the 20th century, people were eating mostly simple, home-cooked meals. Around 2009, about half of what people ate was fast food, or other foods away from home.

This graph actually underestimate the true change, because what people are eating at home these days is also largely based on processed foods.

2. Sugar Consumption Has Skyrocketed

Source: Johnson RJ, et al. Potential role of sugar (fructose) in the epidemic of hypertension, obesity and the metabolic syndrome, diabetes, kidney disease, and cardiovascular disease. The American Journal of Clinical Nutrition, 2007.
Added sugar is the single worst ingredient in the modern diet.
Numerous studies show that eating excess amounts of added sugar can have harmful effects on metabolism, leading to insulin resistance, belly fat gain, high triglycerides and small, dense LDL cholesterol… to name a few .
There is also a plethora of observational studies showing that the people who eat the most sugar are at a much greater risk of getting type 2 diabetes, heart disease and even cancer.
Sugar is also fattening, partly because it doesn’t get registered in the same way as other calories by the brain, making us eat more. It also has adverse effects on hormones related to obesity.
Not surprisingly, studies show that people who eat the most sugar are at a high risk of future weight gain and obesity.

3. People Gain Lots of Weight During The Holidays, Which They Never Get Rid Of

Source: Dr. Stephan Guyenet. Why do we Overeat? A Neurobiological Perspective. 2014.
Most people don’t gain weight overnight… it happens slowly, over years and decades.
But the rate is uneven throughout the year and spikes dramatically during the holidays, a time when people tend to binge on all sorts of delicious holiday foods and eat much more than their bodies need.
The problem is that sometimes people don’t lose all the weight back. They might gain 3 pounds, but only lose 2 after the holidays are over, leading to slow and steady weight gain over time.
In fact, a large percentage of people’s lifetime weight gain can be explained just by the 6 week holiday period.

4. The Obesity Epidemic Started When The Low-Fat Guidelines Were Published

Source: National Center for Health Statistics (US). Health, United States, 2008: With Special Feature on the Health of Young Adults. 2009 Mar. Chartbook.
There was an epidemic of heart disease running rampant in the U.S. in the 20th century.
A lot of scientists believed fat, especially saturated fat, to be the main dietary cause of heart disease (although this has since been disproven).
This led to the birth of the low-fat diet, which aims to restrict saturated fat. Interestingly, the obesity epidemic started at almost the exact same time the low-fat guidelines first came out.
Of course, this doesn’t prove anything, because correlation doesn’t equal causation.
But it does seem likely that putting the emphasis on saturated fat, while giving processed low-fat foods high in sugar a free pass, may have contributed to negative changes in the population’s diet.
There are also massive long-term studies showing that the low-fat diet does NOT cause weight loss, and does not prevent heart disease or cancer.

5. Food is Cheaper Than Ever Before

Source: Dr. Stephan Guyenet. Why do we Overeat? A Neurobiological Perspective. 2014.
One factor that has most likely contributed to increased consumption is a lower price of food.
From the graph above, you see that food prices have dropped from 25% of disposable income to about 10% of disposable income in the past 80 years.
This seems like a good thing, but it’s important to keep in mind that real food isn’t cheap… it’s processed food.
In fact, real foods are so expensive that a lot of people can’t even afford them. In many poor neighborhoods, they don’t even offer anything but junk food, which is often subsidized by the government.
How are poor people supposed to stand a chance if the only food they can afford (and access) is highly processed junk high in sugar, refined grains and added oils?

6. People Are Drinking More Sugary Soda and Fruit Juices

The brain is the main organ in charge of regulating our energy balance… making sure that we don’t starve and don’t accumulate excess fat.
Well, it turns out that the brain doesn’t “register” liquid sugar calories in the same way as it does solid calories.
So if you consume a certain number of calories from a sugary drink, then your brain doesn’t automatically make you eat fewer calories of something else instead.
That’s why liquid sugar calories are usually added on top of the daily calorie intake. Unfortunately, most fruit juices are no better and have similar amounts of sugar as soft drinks.
Studies have shown that a single daily serving of a sugar-sweetened beverage is linked to a 60.1% increased risk of obesity in children.
Sugar is bad… but sugar in liquid form is even worse.
7. Increased Food Variety Contributes to Overeating and Weight Gain

Source: Dr. Stephan Guyenet. Why do we Overeat? A Neurobiological Perspective. 2014.
One factor that contributes to overeating is food variety.
The graph above shows a study where rats were split in 3 groups… one group got regular healthy chow, the second group got one type of junk food, but the third got multiple types of junk food at the same time.
As you can see, the rats eating one type of junk food gained more than the ones eating rat chow, but the rats eating multiple types of junk food gained the most… by far.
There is some evidence that this is true in humans as well. When we have more types of foods available, we eat more… and sometimes more than our bodies need.

8. People Don’t Burn as Many Calories When Working

Source: Church TS, et al. Trends over 5 Decades in U.S. Occupation-Related Physical Activity and Their Associations with Obesity. PLoS One, 2011.
A lot of people blame obesity on decreases in physical activity, that we’re just burning fewer calories than we used to.
Although leisure time physical activity (exercise) has increased, it is also true that people now have jobs that are less physically demanding.
The graph above shows how people are now burning around 100 fewer calories per day in their jobs, which may contribute to weight gain over time.

9. People Are Eating More Vegetable Oils, Mostly From Processed Foods

The fats we are eating have changed dramatically in the past 100 years or so.
At the beginning of the 20th century, we were eating mostly natural fats like butter and lard… but then they were replaced with margarine and vegetable oils.
Most people aren’t frying real food in vegetable oil, they are getting it from processed food. Adding these oils to the foods increases the reward and caloric value, contributing to overconsumption.

10. The Social Environment Can Strongly Affect Calorie Intake

Source: Dr. Stephan Guyenet. Why do we Overeat? A Neurobiological Perspective. 2014.
The social environment is another factor that determines calorie intake. For example, eating in a group can dramatically increase the number of calories consumed.
According to one paper, eating a meal with several people can increase calorie intake by up to 72%, or 310 calories in a single meal.
There are also studies showing that people tend to eat more during weekends.

11. People Are Sleeping Less

Source: Cauter EV, et al. The Impact of Sleep Deprivation on Hormones and Metabolism. Medscape, 2005.
Sleep is often overlooked when it comes to weight gain and obesity.
It is known that poor sleep has negative effects on various hormones that are related to weight gain, and can contribute to increased hunger and cravings.
In recent decades, average sleep duration has decreased by 1-2 hours per night. The reasons for this are numerous, but increased artificial lighting and electronics are likely contributors.
As it turns out, short sleep duration is one of the strongest individual risk factors for obesity. It is linked to an 89% increased risk in children, and a 55% increased risk in adults.

12. Increased Calorie Intake

Source: Dr. Stephan Guyenet. Why Do We Overeat? A Neurobiological Perspective. 2014. (Data from CDC NHANES surveys and USDA food disappearance data)
People may argue about the causes of obesity… whether it is sugar, carbs, fat, or something else.
But one indisputable fact is that calorie consumption has increased dramatically over the past few decades.
According to studies, this increased calorie intake is more than sufficient to explain the increases in obesity.
But it’s important to keep in mind that it is not some collective moral failure that drives the increased calorie intake.
All behavior is driven by the underlying biology… and the way the diet and environment have changed has altered the way our brains and hormones work.
In other words, these changes have caused malfunctions in the biological systems that are supposed to prevent us from getting fat.
This is the underlying reason for the increased calorie intake and weight gain, NOT a lack of willpower, as some people would have you believe.

 By Kris Gunnars