Do you ever find that when you’re being ‘good’ with your diet, you’re really good in the morning. No muffins for me!

Pretty good at lunch. I’ll take the sushi instead of the schnitzel thanks.

And by 3pm? If I open the work pantry and there happen to be TimTams, it’s not my fault if they fall into my mouth.

Well, you’re not alone my friend. There is a real scientific concept called decision fatigue.

From the moment we wake up, we’re forced to make all these small decisions. What to wear, what to eat, when to leave, how long to spend on Instagram.

And this literally drains our brains of power.

In fact, a study on this topic found that judges hearing parole cases were more likely to grant parole in the morning, when they were fresh and unfatigued. When they got tired and cranky, it was easier just to say ‘no, go back to jail’.

The one variable was that straight after lunch, they perked up and started saying yes more. Until TimTam o’clock, that is.

There’s a really cool article about it here if you’re interested. One of my faves, James Clear, also has a great post.

But the take-outs for me, in relation to money, were three-fold.

1. Don’t shop at night – I’m as fond of a Thursday night jaunt as the next girl. But if you’re tired and over work, there’s a good chance you’ll make questionable decisions about what to buy.

Of course, we may have shopping emergencies (who doesn’t?). But in general, try and save your shopping sprees for a weekend morning, or at least a lunch break after you’ve eaten. Much better chance of buying something you actually need and like.

Similarly, cruising the ASOS or Iconic websites in front of the TV might not be the best habit if you’re trying to save money.

Maybe just limit yourself to filling your shopping cart but not hitting the checkout til the next day. You’ll feel differently in the morning – I very rarely make a purchase in this scenario.

2. Sometimes a ban is easier than moderation – If you’re trying to make decisions about whether to buy something, and you’ve already made a bunch of choices that day, it’s pretty easy to say ‘bugger it, spend the money’.

But what about if it’s not even an option? No decision required in that case.

If I’m trying to save money, I ban myself from shopping for a month. I also find it easier for losing weight. For instance, if I have to try and weigh up whether to have a wine, I usually go with yes.

But if I just say ‘no booze in October’, then I don’t expend energy trying to justify it.

I get that not everyone works like this (the rebels among us). Some people just need to break a rule as soon as they impose it.

So, my friend Jo said that when she moved to being a vegetarian, she gave herself a ‘once a week’ option of eating meat. She didn’t end up using it much, but was comforted by that slice of freedom.

So maybe it’s not a shopping ban – instead, it’s ‘I can buy one piece of clothing this month’. And you may not even find anything. But the rebel in you will feel ok about not being told what to do.

3 . Automate the shit out of everything – One of the most important parts of achieving financial security is to pay yourself first. In other words, put your savings aside in a nicely inaccessible account as soon as you get paid.

Do you ever spend the weeks after payday going out, buying lunches, hitting the shops and all that cool stuff, and then seeing how much you have left over to save? If so, the odds are it’s a big fat zero.

So try and automate things like saving and paying bills. Have a direct debit into various accounts. Check out this post for some tips on how to structure your bank accounts – boring but possibly life-changing!

So there are three things that science can help you with, and they apply to other good behaviours too. One of the reasons I food prep like a boss (some of my tips here) is that it takes away the need to decide. You don’t have to weigh up healthy or unhealthy, expensive or cheap. You just eat your darn curry and shut up. It’s strangely liberating, I promise!