The experiment could have been called a form of torture.
Psychologists Claire Adams and Mark Leary invited young women who were watching their weight into the laboratory and actually encouraged them to eat doughnuts and candy (for the good of science, of course). 
Although their experiment seemed like torture, their intentions were good. The question on their minds:
Will people indulge less if they do not feel guilty about it?
Most of us, including myself, would scoff at such a hypothesis.
If they don’t feel guilty, then what is stopping them from eating ALL of the doughnuts and candy? How will they hold themselves back if they don’t feel bad about giving up on their diets?
To find the answer, the researchers separated these dieting women into 2 groups. Then they attempted to make 1 of the groups feel better about skipping on their diets, while allowing the other group to feel guilty about it. Then they would measure which group indulged in more doughnuts and candy.
To accomplish this, they told the women that they would be participating in 2 different studies: the effect of food on a person's mood, and another which was a taste test of several different candies.
In the first study, each woman was asked to choose between a chocolate or glazed doughnut and finish it within 4 minutes. Then they were instructed to wash it down with a full glass of water. The doughnut and the water would make each woman feel both guilty and uncomfortably full at the same time.
Before the second study, the “feel better” group received a message to help relieve their guilt. The message stated, "sometimes participants feel guilty about eating a whole doughnut but you shouldn't be too hard on yourself about it. Remember that everyone indulges sometimes."
The “feel guilty” group didn’t receive any message and was left to their own thoughts and feelings.
Then the experimenter gave both groups 3 large bowls of candy – Reese’s, Skittles and Peppermint Patties – and asked each woman to sample each candy, then rate it. They were encouraged to eat as many candies as they’d like in order to achieve a “definite rating”.
After each group of women ate the candy, the researchers weighed the bowls to see if there was a difference in how much each group had eaten.
The women who received the "feel better" message ate about 28 grams of the candy compared to almost 70 grams eaten by the women who were left to feel guilty.
So those who were invited to feel better about indulging ate less than half of what those who felt guilty ate!
Since this experiment, researchers have attempted similar ways of testing people’s guilt all with similar results. Feeling guilty always leads to indulging more.
WHY FEELING GUILTY DOESN’T WORK
The results of these experiments don’t make sense to a lot of people – including myself.
If we do not feel bad about giving in, how do we stop ourselves from doing so?
Let's take a look at what was happening in the brains of the 2 groups of participants. The "feel guilty" group had just broken their diet by eating a doughnut and was feeling full from the water. This triggered an emotional feeling of guilt.
Our emotional responses are activated in an area of the brain known as the limbic system. This area of the brain is short-term minded. It wants to indulge. It is where cravings for food, sex and even impulse purchases are created. So by feeling guilty, you are giving the part of your brain that wants to indulge more power. 
The "feel better" group, on the other hand, received a message that made them feel better, but it was also very rational. It is true that everyone indulges sometimes! This caused the brains of the "feel better" group to think less emotionally and more rationally.
Our rational thoughts are formed in an area of the brain known as the pre-frontal cortex. This part of the brain is long-term minded. It motivates us to exert willpower and self-control. So by seeing the situation more rationally and forgiving yourself, you are giving the part of your brain that's responsible for willpower more power. 
ALTERNATIVES TO FEELING GUILTY
So now that we know that feeling guilty isn’t the answer, what can we do instead?
Here are 3 scientifically proven strategies that you can use to rebound from a setback and stick with your goals:
1. CONSULT YOURSELF LIKE YOUR BEST FRIEND
Imagine rather than yourself trying to accomplish your goal, it is your best friend instead. They are struggling to stick with their plans and are confiding in you to help them with their problems.
What advice would you give them? Would you try to make them feel guilty about the fact that they are not able to make it to the gym? Or make them feel guilty about choosing the burger and fries instead of the salad?
Of course not. You know full well that shaming them won’t help them in achieving their goal. What they need right now right now is encouragement.
You would tell them that they are only human and all humans go through struggles like this. You would remind them of times in the past that they have faced adversity and overcome it and help them believe that they can do it again.
So why do we never take this approach when it comes to consulting ourselves?
It has actually been proven that we give our best friends better advice than we give ourselves. Because we can see the situation more objectively, we can provide a more thoughtful response. There is less emotional attachment, so we think more logically. 
The next time you start to feel guilty about a setback on the path toward your goals, pause. Think about what you would tell your best friend if they were in your situation. The advice you would give him or her may just be the advice you should give yourself.
2. LEARN FROM YOUR MISTAKES
One of the first goals for humans across the world is to learn how to walk. From the first moment we laid eyes on our parents walking upright, we wanted to do so ourselves.
So for months and months, we tried our best. We began by crawling. Then we started pulling ourselves up with furniture. Then taking a couple steps with our parents holding our hands. Then falling. Then falling again. And again.
Did falling make us feel guilty?
Of course not. Falling is simply part of the process. It is a necessary setback that every person deals with when learning how to walk. When we fell, we were encouraged to try again, and again. Until eventually we started walking on our own. Taking each step with pride.
Why should our goals today be any different? Any goal worth having is going to push us out of our comfort zone just like walking once did. And just like with walking, we are going to make mistakes and fall down.
The important thing is that we learn from these failures. We learn that those morning doughnuts tempt us, so we make sure to have some fresh fruit on hand to eat instead. We learn that we are too exhausted to make it to the gym after work, so we plan to work out in the morning instead.
If we learn from our mistakes, rather than feel guilty about them, we can use them as guides. We can use them to plan for our future success and make the necessary adjustments to stay on the path to our goals.
3. FORGIVE YOURSELF
In my first venture as an entrepreneur, I failed miserably. I raised thousands of dollars of my friends and family’s money, then I recruited 2 business partners to join me and do the same.
I spent over 2 years of my life spending that money on a venture that would prove to be hopeless in the end. The sadness that I felt when we eventually had to close the doors was incredibly difficult for me to deal with.
Now, would the best strategy for me at that point in my life be to feel guilty? To tell myself that I’m a hopeless loser who can never do anything right?
For one last time, of course not. I knew the only way I was going to earn back my friends’ and family’s money was going to be to forgive myself. I needed to learn from this experience and use it to make me stronger.
Wallowing in guilt and pity decreases your motivation and your willpower. Belief in yourself is one of the strongest natural motivations you have. When we believe that we can accomplish something, the part of our brain responsible for willpower becomes more active and stronger. 
If you forgive yourself for failure, as the dieters in the experiment did and I did with my first venture, then you can tap back into this part of the brain. If you allow yourself to wallow in your guilt, however, you will only dig yourself into a bigger hole.
It is natural for us to feel guilty when we are unable to live up to our own high standards. We believe that if we don’t feel bad about failing, then how will we ever avoid failure in the future?
These feelings are natural, but they are also dangerous. By feeling guilty, we are literally draining our willpower and only increasing the likelihood that we will fail again in the future.
So be stronger than your need to feel guilty. Ask yourself what you would tell a friend if they were in your situation, learn from your mistakes, and forgive yourself. You may just find that you are back on the right track before you know it!
- Adams, C., & Leary, M. (2007). Promoting Self–Compassionate Attitudes Toward Eating Among Restrictive and Guilty Eaters. Journal of Social and Clinical Psychology, 26(10), 1120-1144.
- Wise, R. (2002). Brain Reward Circuitry. Neuron 36.2: 229-40
- Heath, C., & Heath, D. (2013). Decisive. New York: Crown Business.
- McGonigal, K. (2012). The willpower instinct: How self-control works, why it matters, and what you can do to get more of it. New York: Avery.