The dark side of junk food

I have been hooked by the topic of junk food. I wrote several posts based my previous knowledge: Obesity is not a personal choiceWhy fast food is not banned? and “Supersize me” surprises me. Now I continue reading articles, watching documentaries, looking for research evidences on this topic. The more I dive in, the darker it gets. The extent of the problem is much larger than I expected. The complexity of this issue is far beyond my imagination. I will summarize some of the things that I learned below:

  1. Junk food* makes people getting addicted the same way as cocaine. Ironically, most people believe drug dealers should be put into prison but they support food industry by saying that being fat is due to lack of self control and will power. They should as well support drug dealers because taking cocaine is a personal choice.
  2. Exercise can only burn off a small fraction of the calories we consume daily. It takes 42 minutes of cardio to burn off a Big Mac, another 40 minutes for the large french fries and again 30 minutes for the large coca cola. So if you eat one Big Mac meal, you need to do cardio for 2 hours to burn it off! And this is only 1 meal in the day. Exercise is good for health but not very helpful in losing weight if you do not change your diet.
  3. Junk food is the modern tobacco. Food industry is doing the same thing as tobacco company: poisoning the world. The only difference being food industry can do whatever they want without any restrictions, even targeting the children.
  4. Junk food with Low-fat label is loaded with sugar or artificial sweetener, which is not any better than fat. It makes people think that they are eating healthy food thus they will consume more.
  5. Junk food is everywhere, not only in fast food restaurants, supermarkets, vending machines, but also in schools, book stores, petrol stations, hospitals, office buildings. No matter where you go, you can see junk food within your reach. If there is alcohol everywhere, can we control the prevalence of alcoholism? Then how could it be possible to abate the surge of obesity if our living environment is filled up with all these addictive food?
  6. To eat healthy is a tough battle between you and the whole environment you live in. You need to be a superman to fight against millions of enemies jumping onto you everyday, food advertisements on TV, internet, newspaper, radio, in the metro, the shops, on the street; fast food restaurants on the streets, in the shopping centers, in the school, near the office; thousands of packages in the supermarkets, convenient stores, book shops and many more.
  7. Whenever the government tries to impose regulations on food industry, people get excited and start calling “Nanny state”. “The government is trying to control what we eat.” “I have the right to eat whatever I want.” Thus the battle against the food industry has never been successful though all doctors and nutritionists are advising people fast food and processed food are bad for health.
  8. This is the strange situation of our modern times: we know junk food is bad for health and we let the food industry do whatever they want, including advertising and selling it to our children. No parents would give a cigarette to a toddler but many would add coca cola to the milk bottle.

*Junk food includes fast food and all kinds of processed food.

Obesity is not a personal choice

“There is no good food or bad food. There is good diet and bad diet. Consumers should be responsible for their choice of diet.” This is the excuse the president of conMexico used to defense the food and beverage industry. The underlying message is that we are not responsible for obesity epidemic. The people who consume our products are. We try our best to make our products attractive and accessible. If the people consume them and get fat, it’s their own problem. Does that sound reasonable to you?

As I explained in my previous post Obesity and Evolution, we are naturally attracted to high-calorie food. Our body is designed to store fat when food is abundant. We are biologically obese-prone species. Choosing healthy, less calorie-dense food is “unnatural” for us. Most obese people do not want to be obese but the food environment surrounding them leaves them with no choice.

Genetic factors and personal diet choice do play a part but the major driving force of obesity epidemic are the environmental factors. Presence of fast food outlets, junk food in supermarkets, food advertisements on media, food prices are pushing people to choose high-calorie low-nutrient food, leading to over consumption of energy and micro-nutrient deficiency at the same time.

Despite billions of dollars spending on interventions and programs targeting obesity and related chronic conditions, not a single country in the world has successfully abated the surging rate of obesity. Why so? Almost all these programs are focusing on changing consumers’ choice, educating and monitoring them to choose healthy food and do exercise. If consumers’ choice is not the main cause of obesity, changing it will not reverse the trend.

Environmental factors are the ones to target for. Imagine if there is only healthy food in the supermarket, people will not buy packs of coca cola and potato chips back home. If fast food is banned, children will not eat burgers and fried chickens everyday. None of the interventions on consumers’ choice would be as effective as this. Then Why fast food is not banned? Fighting against food industry is not an easy task. The government may suffer huge economic loss and may not gain popularity. Thus they will not take any action unless we, the consumers, push them to do so. 

Obesity is not a personal choice. We should ask for a change in our environment to make it healthy for us and our children. If you are interested in knowing more on this topic, check out this documentary Globesity: Fat’s New Frontier.

Why fast food is not banned?

The war on tobacco continues till today ever since the link between tobacco and lung cancer was established in 1952. Governments around the world have taken various measures of tobacco control such as taxing, ban cigarette advertising, plain packaging, education etc. The prevalence of daily smokers decrease steadily over the years in most countries, except Russia. The graph below is made from data in OECD factbook 2013 on Google public data.

daily smoker

What about fast food? It has been proven to be unhealthy, causes obesity, increases risk of diabetes and heart disease. The consequences are much more severe than tobacco. Why fast food is not banned? Fast food outlets are standing up at almost every street corner and in every shopping malls all over the world. Fast food advertisements are on TV, at bus stop, in the subway, and anywhere else we lay eye on. Hundreds of fast food ads are bombing the children in the US.

Fast_Food_Advertising_n

McDonald’s is promoting happy meals to children and dollar meals to the poor without any restriction.

McDo

Why is it so? How come the government is not taking any action to control fast food, like what they did for tobacco? What is the dark truth behind it?

Most people who are against fast food ban cited reasons such as free will, freedom of choice, cheap (thus can feed the poor), fast, taste good. These reasons sound so lame, much like a child cry for a toy. They must be against tobacco control as well for the same reasons. They may not be the ones who get sick due to fast food, since they are healthy enough to surf the internet and shout out their opinions.They are not aware that their choice is affecting other people’s choice, especially children who are too young to make rational choices and poor people who do not have many choices. Because of their preference to fast food, fast food is colonizing the world. Children are used to fast food because it is surrounding the school and their house. Poor people are addicted to fast food because it is cheap and everywhere. Fast food may not make you sick but your choice can indirectly make other people sick. 

I can’t find out the real reason why fast food is not banned. I have listed below some might-be reasons:

  1. Solid research is needed. The current evidences are not strong enough to push the government to impose the ban on fast food. Unbiased, high quality research studies are needed to further confirm the harms of fast food on health. The studies would be difficult to carry out or get published due to the pressure from fast food industry.
  2. Tax revenue from fast food. As such a fast-growing industry, fast food outlets are generating huge tax revenue for the government. The government may be reluctant to close down a prosperous revenue-generating business even though it has negative impact on people’s health. Chemical factories are not banned though they causes air and water pollution that harms people’s health. Same goes for fast food.
  3. Strong lobbying by fast food. Fast food chains are powerful international corporations that can have a say on government policy. Their lobbyists are penetrating into the circle of decision makers and affecting national policies such as dietary guidelines and health programs. A bill that suggests fast food ban will be immediately rejected by their supporters.

What we can do as consumers is not contributing to their business. And tell our friends and family to stay away from fast food too. If everybody does so, the problem is solved.

Do not buy fast food. It kills.

Make your personal healthy diet plan

Diet does not mean a short-term crush course on weight loss. It’s about what you eat and drink every day. Diet is a very personal thing. No one can control your diet except yourself.

There are so many diets advocated by doctors, nutritionists, dietitians, fitness coach, or even your neighbor. Each of them claims that it can make you loss weight and reduce risk of diseases. It is very hard to decide which diet fits you. It is even harder to strictly follow a certain diet for a long time. I think the easier and more feasible way is to create your own healthy diet plan according to your taste and eating habit. Since you can still eat what you like, you will be more likely to keep up with it.

Here are a few principles that you should follow when making your own diet plan:

  1. Eat real food. Real food is food that grows from the soil and can be eaten in their original form. Fresh fruits, vegetables, nuts, seeds, legumes, etc. Try to make them the major part of your diet. For example, eat fruits and nuts for breakfast and snack, and replace the dessert with raisins or dates. If you can afford organic, keep to it. If not, just carefully wash the food before eating. Never refuse real food because of the fear of insecticide residual. The benefits you get from eating real food far exceed the potential harms.
  2. Eat in moderation. No matter how good the food is, do not eat too much. Stop eating when you are 70% to 80% full. It takes about 20 minutes for your brain to realize that you are full. If you keep on eating till you receive the feedback from your brain on satiety, you have already over-eaten, at least 20% more than what you need. This is a major threat for your weight control.
  3. Avoid any refined, processed food and drink. This includes all the nice-looking packages that fill up 90% of the shelves in the supermarkets. If you want to control what goes into your body, avoid all these as much as possible: coca cola, packaged fruit juice, potato chips, cereals, ready-made microwave packages,  and anything else with ingredients that you cannot pronounce. Milk, oil and cheese are also under this category. If it is not possible to avoid them completely, choose those less-processed such as extra virgin olive oil, fresh milk without added sugar. Replace white rice and bread with brown rice, whole grain bread, quinoa, beans can help lower blood sugar.
  4. Avoid trans-fat and added sugar/artificial sweetener, limit saturated fat and salt intake. If you can avoid processed food and drink, you have already get rid of trans-fat and added sugar from your diet. I put it as a separate point because it deserves all your attention. Anything with trans-fat (potato chips, nutela, fried chicken, french fries, coffee creamer. margarine, cakes/cookies made with vegetable oil) should be forbidden. Anything with added sugar/artificial sweetener (soft drinks, packaged fruit juice, candies, cookies, syrup) should not enter your house. If you crave for sweetness, bake your own cakes/cookies at home. Make your own fresh fruit juice from real fruits. Saturated fat and salt can be part of your diet but they should be taken in moderation. There are debates going on over their harms and benefits but you would not want to experiment with your own body I suppose. To play safe, limit their intake.

Try to make your own diet plan according to the 4 principles. You will find it easier to follow than the diet made by experts. Do not aim too high. Make the change gradually but steadily. Here are some tips to achieve your diet plan:

  1. Cook at home as often as possible. This is the best way to control what you eat. Buy real food, control the amount you eat, limit added sugar and salt, avoid processed food, all these can be easily achieved if you cook your own meal at home.
  2. Stay at the fresh product section in the supermarket. When you go to the supermarket, directly walk to the rear where the fresh products are. Fill up your shopping basket there and leave. Do not go to those rows of shelves in the middle with all the packages. You don’t need them.
  3. Drink water. Water is the cheapest and most effective pill for weight control. Do not buy any sugary drinks. Buy a water bottle and drink water.
  4. Eat slowly and do not eat alone. Take your time to eat. Eating is an enjoyable process. Relax and enjoy the taste of food. If possible, eat with friends and family whenever you can. Turn off the TV and put down your phone when you eat.

Be nice to yourself. Be kind to your body. Eat healthy food and enjoy the food. 

 

Low-fat diet is not the devil

The recent report  Eat fat, cut the carbs and avoid snacking to reverse obesity and type 2 diabetes by National Obesity Forum has stirred up a heated debate over fat consumption. It has been featured on the Guardian, Independent and The Telegraph. The main point of the report is: fat is not the devil, carbs are. It also advises on eating “real” food and avoid processed food.

Since the recommendations in the report are against the low-fat diet guidelines by US and UK, the headlines state the low-fat diet as “disastrous” or the NOF diet advice “extremely dangerous”. Some even claims that low-fat diet is the main cause of the obesity epidemic in the US by showing that obesity prevalence shot up after the low-fat diet published in the 1977. I wonder if these people serious believe what they are talking about or they just want to hit the headlines and become famous.

Let’s be rational. How many people actually follow the guidelines? Do the guidelines have any effect on people’s eating behavior? I will use the color wheels from What the world eats, that I wrote about in my previous post What the World Eats from 1961 to 2011 to illustrate this.

 

Here are two color wheels showing the US daily calories consumption in year 1976 and 1978, before and after the low-fat guidelines were published.

US 1976 1978

Do you see any difference? Do people follow the guidelines and eat less fat and more carbs? Not at all. Well maybe it takes some times to see the changes. So let’s look at the wheel for year 2011.

US 2011

Percentage of each type of food consumed is largely the same. There isn’t any significant increase in carbs or decrease in fat. What’s more, people are consuming 500 cal more every day in 2011. What does that means? Very obvious, people do not follow the diet guidelines. It is extremely difficult to change people’s diet. Even those diet interventions with long term intensive follow up and monitoring, hardly change people’s eating behavior. Every guideline advises to limit sugary drinks. How many people actually listen? If the guidelines can have such huge impact, so huge as to cause the obesity epidemic, the government doesn’t need to spend millions on diet interventions any more. If people do follow the diet advice, limiting their daily calories intake within the recommended range, there will not be so many obese people around the world. How can we term it as “disastrous” and blame it for causing obesity when it simply doesn’t have any impact on people’s diet? 

I agree that the low-fat diet has its limitations. But that’s the case with all kinds of diet advice. Diet advice cannot be perfect because the current available evidences are not able to tell us every single component of our diet is good or bad for our health. The reason being it is almost impossible to carry out randomized trials on a single diet component. Even for trials comparing two types of diets, low-fat vs high-fat for example, it is impossible to make sure people actually follow the assigned diet in the trial.

The main difference between the low-fat diet and NOF diet advice is on saturated fat. Low-fat diet recommends limited intake of saturated fat while NOF report argues saturated fat is not harmful. It is meaningless to argue who is right or wrong when the evidences are not strong enough to support either side. Meanwhile, let’s play safe and eat saturated fat at moderation.

 

What the World Eats from 1961 to 2011

National Geography has made this amazing website What the World Eats. It uses colorful wheels to show what people eats everyday in 22 different countries. The size of the wheel is proportional to the daily total calorie intake. The colors represent different types of food consumed including grain, meat, dairy&eggs, produce, sugar&fat and others. When you click on the forward arrow below the wheel, it will show you the changes of this wheel from 1961 to 2011, which is very interesting.

By playing with these graphs, you can get remarkable insights on diet patterns around the world and how it evolves in the past 50 years. These two color wheels are taken from the website. They showed the source of world daily calories intake in 1961 and 2011. By comparing them, we can make the following conclusions:

world daily calories

  1. From 1961 to 2011, world daily calories increased from 2194 cal to 2870 cal. 2870 cal is far exceeding the recommended daily calorie intake (2500 cal for man and 2000 cal for woman), partly explains the increasing trend of obesity globally.
  2. The 676 cal extra calories comes from mainly meat (132 cal to 272 cal) , sugar&fat (345 cal to 570 cal), grain (1085 cal to 1296 cal).
  3. There is not much changes in the composition of the food wheel in terms of percentage.

Thus extra calories from meat, sugar&fat and grain most likely contributed to the global obesity epidemic. 

Now let’s compare USA, China and India from year 2011, the three countries with the highest number of obese people in the world. Though the prevalence of obesity in the USA is over 30%, while that in China and India is lower than 5%.

world daily calories 3 COUNTRIES

There are several amazingly interesting discoveries to be made:

  1. The US food wheel is almost 50% larger than the Indian wheel. US daily calories is 3641 cal, about 1.5 times of India (2458 cal).
  2. Sugar&fat takes up much larger potion in the US wheel, as high as 37%, while in China it is only 11%.
  3. % of grain is surprisingly low in the US (22%), while it is 57% in China and as high as 57% in India.
  4. % of meat is only 1% in India due to religious vegetarianism and scarcity of food in rural area.

We won’t be able to make any conclusion on the causes of obesity from this comparison. What we can see here is the distinct difference between American diet and Asian diet. Americans are consuming more sugar, fat, dairy and eggs, but less grain. And the Americans eat A LOT. Every day, people are eating 50% more than they should all over the country! Can you imagine? Incredible indeed.

 

Obesity and leptin resistance

In search for the causes of obesity, I came across this wonderful lecture by Stephan Guyenet on What causes leptin resistance? as shown below. Stephan is an obesity researcher and neurobiologist. His blog Whole Health Source is full of useful information on obesity and nutrition.

This video contains technical terms on cell signaling pathway and biochemical research. If you have some training in these fields, please watch the video. If you find it difficult to understand, I have summarized the main information in plain language below.

Leptin is the satiety hormone that prevents you from getting fat. When your adipose tissue (the fat cells) stores up fat, it secrets leptin. Leptin travels up to your brain and your brain will tell you to eat less and spend more energy, and thus to reduce fat in your body. As illustrated in the graph below taken from Stephan’s video lecture.

Leptin fat cycle

This is a sophisticated circular system that ensures our body fat remaining relatively constant over time. This system works perfectly well unless it is disrupted by the following factors: excessive leptin, inflammation and lipid metabolites. Let’s explain these factors one by one:

  1. Excessive leptin: Leptin level is proportional to body fat mass. So if you have too much body fat, it will produce excessive leptin, which disrupts the leptin-fat cycle. The consequence is: your brain doesn’t tell you to stop eating and you will keep on take in more calories and storing more fat. More fat->more leptin->more fat. Your body becomes a fat production line without a stop button! Pretty scary, isn’t it?
  2. Inflammation: We all have millions of gut bacteria in our digestive system. They help us with the digestion and nutrient absorption and live in harmony with us. But if we keep on eating unhealthy diet, our gut cells become “leaky” and these harmless bacteria can now enter our circular system and cause inflammation. Inflammation will disrupt the leptin-fat cycle and we will lose control of our fatness. What makes it worse, excessive fat mass is also inflammatory. This viscous cycle goes on and make us obese.
  3. Lipid metabolites: The fat we eat is normally metabolized and used as energy source for the cells. But when there is too much fat, the lipid metabolites accumulates in the cells and make the cells less sensitive to leptin. Thus the leptin-fat cycle is disrupted and we will enter the viscous cycle that leads to obesity.

The following diagram (also taken from Stephan’s lecture) summarizes the causes for leptin resistance:

leptin causes

Take away message from this lecture is: overeating, obesity, unhealthy food (especially refine, processed food) and inactivity can lead to excessive leptin, inflammation and lipid metabolites, which in-turn causes leptin resistance.

Leptin and fat are very much like the Chinese yin and yang. They are two opposite forces give rise to each other. When yin gets stronger, yang will suppress it and vice versa. They are in constant movement but at the same time maintains harmony and balance. Thus the balance is maintained all the time unless one gets too strong and break the cycle.

The best way to prevent obesity is maintain the balance between leptin and fat and do not enter the viscous cycle. Eating healthy food and regular physical activity can reduce inflammation and regulate level of leptin and lipid metabolites.

Evolution is selecting skinny people?!

After writing the post Obesity and Evolution, this topic keeps on running at the back of my brain. This morning I suddenly realized evolution has already found its solution! The hard to tell truth is evolution is selecting skinny people! This is the mechanism it finds to fight against obesity. It did not create any new physiological process in our body. Instead it relies on our negative perception of obesity to work its own way out! How clever it is!

The purpose of evolution is not to keep each and every one in the species. It is to select those fittest for survival and let them grow and reproduce.

Just think about the obesity issue from the opposite side : why not everyone is obese? With the abundance of food all year round, and our body’s “store-that-calorie” mechanism, how come there are still skinny people everywhere? Isn’t it against the nature? That’s the key. People have already developed their own way to keep away from extra fat even though they are surrounded by high calorie food. And this makes them more physically fit, have lower chance of getting sick, higher chance of living longer and even more likely to find a partner. Thus they are the fittest for survival selected by evolution and they will pass on their skinny way to their offspring.

This theory is dangerous. It can leads to discrimination against obese people, which already exists. But if we leave out the consequences for the moment and look at the theory itself: is it TRUE?

Obesity and Evolution

How do we get fat? When the calories in is more than the calories out, our body stores up the extra calories as fat. Fat is not all evil. For the early human beings living in the savanna, fat helps them survive famines and keeps them warm. Without fat, human beings may not even exist today.

In our modern days, with the abundance of food all year long, our body keeps on storing up fat but never has a chance to use it up. Our body is not adapted to deal with such huge amount of fat, it deposits the extra fat wherever possible, in the liver, in the blood vessel, beneath the skin, around the internal organs etc. That leads to fatty liver, cardiovascular disease, stroke and increased risk of diabetes. The once good fat becomes evil and makes us sick.

Obesity is not a disease itself. It is a condition that puts us at risk of many chronic diseases. These diseases can seriously affect our quality of life and may even shorten our lifespan. The negative impact of obesity on health is well-known to the public. Not many people would be willing to be obese except in countries where fat is still considered a sign of prosper and beauty, such as Tonga, Fiji, Nigeria. Then why on earth there are so many people obese and the figure keeps on going up all around the world?

The answer is very simple: because we cannot control our body.

Millions of years of evolution has taught our body to store fat for survival. That’s why high calorie food is so appealing to us. High-fat and high-sugar foods are so popular not only because of the advertisements from food industry, but also driven by the force of evolution: calories are scarce, store it whenever you can. If we let our body to choose what we eat, we can easily become a fat factory.

To make it worse, our body naturally resists weight loss because that can decrease our chance of survival in the wild. That’s why it is so difficult to lose weight. Participants of weight loss programs usually lose weight at the beginning but always regain their weight not long after. Constant fat storage + minimum weight loss = obesity.

For millions of years, our ancestors were living with scarcity of food and constant famine. We have created a world full of food that never exists in the natural history, in as short as 50 years. Evolution simply cannot catch up with the changes. The old “store fat whenever you can” mechanism is still in use. Maybe in several hundred years, we will develop a mechanism to limit calorie intake or to get rid of extra fat naturally. But for now, we are suffering from the imbalance between development and evolution.

The driving force of evolution is to keep the species propagate. Since obesity is severely affecting the fertility and mortality of human being, evolution will for sure find a way to fight against it. But it needs time. This is a natural process that may take hundreds, if not thousands, of years. But eventually, it may develop some mechanism that is out of our imagination.