The Cause of Obesity Part 2: Changing Bad Habits

This is the follow up post to The Cause of Obesity – Part 1. Let’s look at why bad habits make it very hard to lose weight and what can be done about them. Again, there is more to weight loss than willpower. 

In order to tackle a problem, you need to determine its root causes. Then, you corner the root causes in the locker room and beat them with a sock full of batteries.

The problem. OBESITY.

Potential root cause. BAD HABITS.

What if I told you that there is actually a field of science that studies habits and that people actually research how you can change your habits?

“I have tried diet after diet and nothing just seems to work”

“I have had 5 gym memberships in the past … just never end up going”

“This one time I tried to only eat apples on this apple diet thing and I only got to Day 3…I still can’t look at apples the same”


For many people, sticking to a diet or an exercise routine can be super difficult because their bad habits are so hard to shake. Let me explain why they are hard to shake off, contrary to what Taylor Swift would tell you (terrible joke, actually shaking my head in disgust right now).

As an old man once told me, “Food doesn’t make you fat, eating it does”. 

Obesity, most of the time, is a problem with eating too much. So why is it that people eat too much when they know it can lead to all these terrible things? The answer comes down to habits my friends. HABITS! Bad ones.

Here is the low down on the science of habits. The following content is based on research that is documented brilliantly in a book called “The Power of Habit” by Charles Duhigg.

Habits, by definition, are automatic behaviours. Through repetition, certain behaviours become “second nature” and form habits.

Life is a series of habits. If it wasn’t, it would be exhausting and we would never be up late enough to watch MasterChef.

Most of your day, sort of just happens.

You brush your teeth. Did you think about what hand you use to hold the tooth brush in or which part of the mouth you start on?

You back out of the driveway. Did you consciously think to put on your seatbelt, put the gear into reverse, simultaneously look at the rear and side view mirror whilst adjusting the radio to find a channel that is actually playing songs?

Ever think about walking? Ok, you get the point.

Each habit, has a “CUE”, a “ROUTINE” and a “REWARD”.

A cue is like the trigger for a repeated behaviour e.g. Wake up in the morning

The routine is what you do e.g. Brush your teeth

The reward is the outcome you wish or expect to achieve after doing the routine.  E.g. feel that tingly freshness in your mouth which you equate with a clean mouth


Well how does this relate to eating? Let’s take a common example.

Sleepy and tired (CUE).

Have a sugary snack (ROUTINE).

Feel energised (REWARD).


Feel bored at work (CUE).

Wander over to the fridge and get a snack (ROUTINE).

Successfully killed time (REWARD).


Once a habit is formed, we experience the wrath of something called “CRAVING”. If it’s a good habit (e.g. exercise), then the craving is your best friend. If it’s a bad habit (e.g. eating too much chocolate), then the craving is the equivalent of explosive diarrhoea.

Cravings occur just AFTER the cue and work to ANTICIPATE the reward BEFORE you even do the routine.

This can be a problem. If you don’t perform your usual routine and satisfy your craving, you may feel frustrated, maybe a bit on edge, annoyed, sad or disappointed.

Ever noticed yourself saying “I am really craving a [insert personal preference] right now”? Until you get it, you just don’t feel quite right. Cravings did this to you! Hmmm, where is my sock full of batteries!?!?!

Same reason why kids go bat sh** crazy when their parents drive past Maccas instead of entering the drive through.

Now that we understand the basic science of habits, the next logical step is to look at how to change them.

Here is a step by step.

1) Identify the routine you want to change e.g. eating chocolates at work.

2) Identify the reward by mucking around with different rewards.

The reward, or WHY you actually do a particular thing, is often not obvious. Keep changing the routine to suit different rewards e.g. try going for a walk (perhaps you just want an energy boost), try eating a donut (perhaps you want a sugar hit), try chatting with a friend (perhaps you just like the socialisation that comes with snacking at work). After you do something, see if you still want to perform the old routine (i.e. snacking on chocolates at work) 15 minutes later. If you do, whatever reward you were searching for still hasn’t been satisfied. If you don’t, and this happens consistently, you have likely identified your reward. EPIC.

3) Identify your cue

Conveniently, “The Power of Habit” shows that cues likely fall into one of these categories:

  • TIME

As soon as your urge to perform the routine hits, write down an answer for each of these categories. Don’t change anything. Just document. After a few days or weeks, you will hopefully start to see a pattern as to what your cue is. Perhaps it’s the time of the day or when you feel tired or when you feel bored.

4) Implement the “Golden Rule of Habit Change”

This states that you keep the cue and the reward the same, and change the routine. For example, if your CUE is feeling tired and your REWARD is to get an energy hit, instead of having a chocolate bar, perhaps a solid routine would be to go for a walk outside and stretch. So the cue and reward are kept the same but, you replace the bad habit with a potentially good one.


  • Habits can be broken into a cue, a routine and a reward
  • Habits are automatic and they are driven by cravings that make it hard for you to resist performing your usual routine
  • Once you clearly identify the cue, routine and reward, you can change the habit by using the “Golden Rule of Habit Change”
  • Obesity sucks

Have a think about some habits you are proud of and some you would like to change. I would love to hear about some of your habits and what you perceive as your cues, routines and rewards.

Conversely, if you have successfully changed habits in the past in your own way and particularly if it relates to weight loss, please share your secret to success.

As always, share this around to anyone who is interested in this topic of beating obesity.

Related posts:

The Cause Of Obesity Part 1: Big Picture

The Cause of Obesity Part 3: Eating Carbohydrates

The Cause of Obesity Part 4: Eating Fats

Weight Loss Solutions: Sustainability

The whole (food) does not equal the sum of its parts 

Much love to all of you and of course, to myself.

Dr G