Q. I have tried to lose weight many times, and I really believe that I know what to eat and what not to eat, but I just can’t seem to stick to any diet. Why is this?

A. This is such a common scenario that you are not alone. I often spend a lot of time with patients who are trying to lose weight, educating them more about the behavioural aspects of weight loss than about the nutritional requirements.

Many people trying to lose weight have been doing so for most of their lives. They are “professional dieters” who have read numerous books, tried many diets and are very well-educated on how to diet. So why are they unsuccessful? I think you want to consider a few possibilities that may apply to your situation.

One thing I believe is necessary when it comes to weight loss is is to have a clear understanding of the difference between wanting to lose weight and being willing to do the work required. It’s much easier to say you really want to lose X amount of weight, or weigh a  particular amount, or look like her or him, or like you did before. Or you want to fit into certain clothes. But are you willing to do the work needed? This is a tough but honest question. If the answer is a resounding, definitive yes, then you are guaranteed success in achieving your goal. If it’s a more hesitant commitment, then you may be in for a bit of an uphill battle or in need of changing your thought process more than just your diet. If you frequently want to eat the piece of cake, etc., in front of you, more than you want to lose the weight, then the cake will often win.

You want to change your thought process from looking at a food and saying or thinking, “I want that and I can’t have it” – in other words, feeling deprived, to instead believing that “I can have it, but I don’t want it, because it’s getting me further away from my goal.”

There may be a few other obstacles at play here, too. Many people unintentionally sabotage themselves, for example, by having tempting food in the house. It’s not good enough to say, “I have willpower. I can avoid all of my favourite foods.” You have to get them out of the house, out of your car, off your desk and out of your purse, or you are setting yourself up for failure. Few people have enough willpower to avoid these temptations, and I think that’s OK and normal.

We all have foods that call our name, foods that when they are in the pantry or on the counter, call to us. So don’t buy them! It’s much easier to walk by them in the grocery store once than to do so in your kitchen a hundred times. I know what you’re thinking – I hear it all the time – “there are other people in the house who eat it too.” They probably don’t need it either.

The other very significant barrier in weight loss often is why we eat. Everyone knows that sometimes we eat if we are bored, depressed or stressed, or simply for social reasons, but it is really important to look at ourselves and evaluate how often we do this, in order to determine if it is having a negative impact on our weight or health. Once we have identified if or when we eat for emotional or social reasons alone, we can start to implement strategies to reduce this behaviour and, more importantly, to recognize when it’s happening.

The last strategy that I find educational for people perpetually struggling to lose weight is probably the easiest – keep a food diary. This entails writing down everything you eat and drink  every day, including portions. You must do this right after eating, and not try to recall accurately at 11 o’clock at night what you ate all day. There are two reasons this works. First, people are often shocked to see what they actually ate while watching TV, for example, or what they snacked on while cooking dinner. More importantly, it makes you think twice about everything you eat when you know that you have to write it down. Committing to black and white is taking ownership, and you will make smarter choices.

For anyone struggling with why weight loss seems difficult to achieve or stick to, consider whether some of these suggestions might apply to you and whether you can adopt any of these strategies to assist you in being more successful.

For every “good” day you have, pat yourself on the back, because it is hard work. Good luck!

Lisa Weinberg is a registered dietitian/nutritionist in Toronto, in private practice and at the Genesis Professional Group. If you have any nutrition questions, please send them to The CJN.