How to lose weight? Part III- How should I eat to lose weight?

Key takeaways:

  • How much you eat depends on what you do during the day;
  • You will need to eat more if you have more physical activities;
  • Overeating has becoming a norm due to abundance of foods and the fun of eating;
  • Overeating causes left-over fuel in your body;
  • Left-over fuel is stored as ‘reserve energy’ in the form of fat;
  • Overeating consumes your energy (for digesting those foods), bad for your body;
  • The magic to lose weight is …. (see the end of this post!).
Note: this post is a bit longer than my usual ones, so be patient!
A piece of meat, some salad and rice; a balanced meal with a fresh beer. Couldn’t be better than this while waiting for my flight.

In ancient times before the era of animal and agriculture farming, it must be hard to find over-weight human because food was scarce. Food was only available through hunting or harvesting in the wild at that time. Human were smart enough to realise that we could farm our foods. Farming solved a lot of food supply problems for ancient human. After that human have had abundant foods to eat, store and even trade.

Since foods are now so easy to get, we tend to eat more than we need. Eating three meals was not a norm in ancient times but it is now. In between meals, we also snack; here comes morning tea and afternoon tea times. Even more, you can have a high tea or a dessert buffet. How nice!

What a wonderful high tea! (Photo by Jelleke Vanooteghem on Unsplash)

In general, we eat a lot; way more than what our bodies need. Eating is no longer for survival for human but mostly for fun. In fact, eating is such fun and joy that most people celebrate achievements or strengthen relationships around dinning tables. So, here comes the ‘overeating problem’.

Overeating is a problem because literally one will eat more than he needs. In Part I of this series, I mentioned that a human body is an ‘input-output system’ and whatever fuel that is not used will be stored. The immediate problem overeating creates is gaining weight; people get fat. How much one eats depends on what he does during the day.

I’m 178cm, 60kg and 47 years old. For my size and my age, my normal daily food intake in terms of energy is 2,200 Cal (or 9211 KJ) with a sedentary physical activity level according to USDA. If I’m moderately active, then I will need 2,400 Cal (10,048 KJ); an active me will need 2,800 Cal energy to fuel (about 11,723 KJ).

Don’t you love home made blueberry muffins? They are both fresh and delicious but have quite some sugar. One a day is satisfying!

I believe most people don’t know these numbers and have no idea how much that calories or kilojoules mean! Let’s put that number into a more meaningful perspective.

A regular McDonald Big Mac meal in Australia, according to the nutrition guide provided by Australian McDonald’s official website is: Big Mac burger- 2,370KJ, regular coke- 512KJ, and regular fries- 1,240KJ. The total energy for a regular (medium) Big Mac meal is about 4,122KJ (about 985Cal). If I work in the office from 9-5 and don’t have much exercise, then having a Big Mac meal as lunch is already 45% of my total daily energy intake. It means that if I eat another Big Mac meal as my dinner, then that’s enough. For that scenario, I am only supposed to have a very light breakfast and nothing else during my day except water.

(A note for American readers: the size of your ‘regular’ coke in a Big Mac meal is actually the ‘large’ size in an Australian McDonald restaurant (yes, we Australians are being short-changed!) and you also get to refill your cup as much as you want in the store! That doesn’t happen here is Australia.)

From the above Big Mac numbers, it seems OK, right? The fact is that we eat more than that during a typical day. We drink coffee, tea, juice and soft drinks and these contribute to our energy intake. We also snack and most snacks are delicious! This usually means they are high in sugar or carbohydrates. Do you know someone who has a snack salad in between meals? I happen to know one but only one among all my colleagues and friends and he is on a strict diet! Some people also drink alcoholic drinks and they are high in carbohydrates (alcohol has high energy!). When we stay late at night, we also snack… hard to watch a nice movie at home without chips, cokes, KFC or pizzas!

Do you love your cappuccino? It’s about 510KJ, the same energy as the regular coke I get in a local McDonald’s. If coke makes you fell guilty, then energy-wise you should feel the same for your cappuccino. But, I guess you don’t know this?

Overeating itself is not a problem; the real problem is how do we ‘burn’ the fuel. Let’s put this into a perspective of doing exercises. I just did a calculation by using the website hosted by the NSW State Government (the State I live in) to see how much exercise I need to do to burn my medium Big Mac meal lunch (4,122KJ). The answer is that I need to swim about 2hrs and 20 mins! By my ordinary swim pace, I should be able to swim about 5-6KM; OMG! Or, I can choose to do vigorous cycling (like hell) for 1hr and 40 minutes. Or, I should run for 2 hours to burn that Big Mac meal; that’s how long I did my half-marathon, 21.2KM run. When we put the energy intake into this perspective, how do you reckon you can burn that Big Mac meal?

The good news is that people hardly have Big Mac for every meal. Also, in order to run our body and maintain regular body temperature, we need to burn energy. So, one will still burn energy by staying ‘still’ for the whole day (if you can), but this amount of energy is not much to offset what we may have taken through eating.

In short, most of us eat more than we need. Left-over fuel is converted and stored in our body (as fat) and this is a natural mechanism to protect us, in case we need the energy ‘reserve’. No wonder overweight is an issue for many people. It’s not your fault; foods are simply so nice to eat and they are so delicious. Can’t resist! >_<

Feel free to eat your burger. Just remember to move more; walking is fine, too!

Ironically, it takes human body energy to digest foods in order to obtain energy from foods. This means that you may spend more energy to digest if you eat more. In fact, feeling ‘exhausted’ during and after digestion is kinda normal. Have you even seen what happens to a snake and a lion after a feast? The snake will find a place to digest the feast and the lion will simply lie there ….. That’s perhaps how we feel after a all-you-can-eat buffet feast, isn’t it?

The magic to lose weight is actually no magic. Scientifically, Ruben Meerman in his book, Big Fat Myths, proved that the only ‘magic’ to lose weight is ….. eat less and move more! What the? Yes, if someone tells you that eating some magic ‘tea or pills’ will lose weight, then perhaps it really ‘helps’. But, if you still eat more than you should, then no magic ‘pill’ can help you lose weight. That’s scientifically proved and that’s a fact.

Don’t be disappointed by reading this! There is still hope for you to lose weight, if you can eat ‘normally’. I will show you how in my next blog post, so see you next week, then. ^_<

Dr. C. Richard Wu @

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