Hunger is the most powerful driver, because without it, we might forget to eat, and eating is essential. But these days most of us rarely get really hungry but the fear of hunger is powerful too.

My cat is a stray and I found her when she was scavenging in my friend’s kitchen. She was skinny and scared. After coming to stay with me she became as fat as fat because food, all of a sudden, was freely available, but starvation had been a daily risk. These are the rules my cat was following, to deal with the serious risk of lack of food and starvation:

• Always eat when food is available
• Always eat as fast as possible
• Always eat as much as possible
• Always eat anything put in front of you

We are animals too, so we can end up following these same rules, even though food is easily accessible and starvation is unlikely. Hypnotherapy can help you by embedding suggestions in your mind to help you overcome these hard-wired behaviours to avoid putting on too much weight.

We usually talk about losing weight, and I think that is a bit too abstract or most of us. We might think about a goal weight and express a desire to reach it. Again, for me, a bit too abstract. And we know that the goal is in the future, and things get a bit less urgent and a bit vaguer. To manage our weight we need to manage our eating and we can make those changes one or two at a time. Hypnosis helps by bedding those changes in, so they become automatic and sustained.

So, if you know that you just eat too much of everything, start eating half of any plate of food in front of you. Some of us were taught to eat everything on the plate, so this new behaviour might need some practice.

Before you eat anything, consult your hunger quotient. How hungry are you at the moment on a scale of 0-10? If it is less than 5, you don’t need to eat. There is always food available later. For some of us, a better question is when did you last eat anything at all? If it was less than 3 hours ago, you wil not be hungry. You might have the desire to eat and your appetite might be strong, but this is not hunger. Most of us have forgotten the difference.

When you eat, eat slowly. Completely finish one mouthful before preparing the next one. Research has shown that if you train yourself to eat slowly, and indeed, if you reduce your eating speed during the meal, you will eat less.

And that is another tip. Eat meals rather than snacks. Snacking is a new habit and since we started doing it, the average weight has increased by over 10 pounds.

Without realising it, our eating is affected by the person we sit next to.

If it is a really fat person, then we will eat a bit less than them. Their weight serves as a warning to us. But if we sit next to a skinny with a huge portion, then we automatically, without thinking, get the idea that it is okay to pile on the food. This research is from the University of Chicago.

We are affected by all sorts of cues when it comes to eating. The modern environment is full of encouragements to eat. This includes a food ad on the telly (research shows that any food on the telly makes us hungry, even if we have just eaten). Or flicking through a slimming magazine (more talk about and pictures of food in these than you would expect). The sight and smell or popcorn in the cinema. Or passing a restaurant fragrant with cooking smells. And then there is habit. What do you pair your unnecessary eating with. Is it 3pm, a cup of tea and a biscuit? Or in front of the telly with the pringles? Or a glass of wine and a bag of nuts?

Sad, perhaps, but true. Women need less energy to run their bodies than men do, and therefore need to eat less than men, even of the same weight, height, age etc etc etc. So it follows that if you eat the same as your man, unless he is really teeny weeny, then either he will shrivel away to nothing or the woman will put on weight.

Women 's portions need to be smaller than men's. How can we achieve this?

The easiest way is to use a smaller plate yourself. This will make it easier for you to estimate a healthier portion. Large plates give us a subliminal message that large portions are okay.

When you have got used to using a smaller plate (it takes a weekend), you no longer have to think about food all the time. Your plate size does it for you.

Eating a large portion does not make you feel more satisfied than eating a small one. That's good news isn't it? So when you eat a smaller portion, you don't physically feel any less content. This research was carried out at Penn State University. So it means that if you serve yourself a smaller portion, you will feel fine. The easiest way to do this is to use a smaller plate. That way you can deceive your eyes about the size of the portion. When your eyes see a full plate, all of you feels that you are not being short-changed.

They also show that people eat more when they are given a larger portion. Indeed, most of us will eat whatever is put in front of us. We do it on an aeroplane, and we do it at home as well!

Saving just 150 calories a day is all you need to do to lose weight. This is an easy way to do it.

The generation that was told to eat everything on their plate find leaving food very tricky.These suggestions from your childhood are persistent and powerful.

So when you go to the fridge and see the remains of a meal, there is a powerful urge to eat it, to avoid waste. Don't tidy your fridge by eating up the contents. Feeling guilty about waste can interfere with our goal to avoid overeating.

So what can we do? Well, hypnosis can embed new suggestions, permitting you to throw food away. In hypnosis, you can learn to always leave your plate half eaten. Breaking the instruction to eat everything up needs a bit of support. However, many of us feel strongly about food waste. Hypnosis can help you develop new habits, simple things like cooking smaller quantities so that you get just the right portion size. You may feel that to be eco-friendly, you can't use the oven to heat up or bake just a small portion, so you might cook a bit more and freeze the rest. You might keep a dog - scraps and bones are apparently the ideal diet! What might be the best approach for you?

But your belly is not the bin. Don't fill it with rubbish.

Portion sizes have doubled over the last 20 years.

American researchers at New York University found that when McDonald’s first started in 1955, its hamburger weighed around 1.6 ounces - 28 grammes. We would think that was pretty mean if we were served it today. The basic hamburger now weighs 100grammes.

I had a look at McDonalds website. There is loads of information, but no mention of the calories in each product. Well, it was hidden away if it is there at all. Find the calories here instead!

McDonalds are an easy target in many ways, because they do provide information. Your local takeaway doesn't measure and count, so you have no idea of the calorie content. I am not a great fan of calorie counting in detail, but if you are trying to control your eating, then it really does help to have a broad idea of where the calories are coming from. I suggest that for most of us, it is not coming from our 3 daily meals.

A double cheeseburger is 440 calories. That is a quarter of the rule of thumb daily allowance of 2,000 calories for women. A basic hamburger is 250 calories, without the regular fries, which are 274 cals. No wonder we all gain weight. This sort of eating is called "hedonic" by the medics. It is fun eating, extra to your normal 3 meals a day. At these calories, you could easily find your "hedonic" eats add up to more than your daily meals. Oops.

Estimating portion size is difficult for all of us, but developing rules of thumb will be handy. Because we have got used to larger portions in restaurants, our estimate of calorie content of a meal gets confused.

Research by Brian Wansink and colleagues shows that everyone (normal weight, underweight and overweight, men and women) has difficulty in estimating the calorie content of a large plate of food, whereas they accurately assess the calories in a more normal portion.

If we are overweight, we tend to have larger portions. That means that those of us who are overweight are making these wrong estimates frequently. As a result, we are underestimating the calorie content of most of our meals, we overeat and so we put on weight. What to do?

These researchers suggest that you should estimate the calories and then double them. A normal meal might be 500 calories. If you are overweight and you know that you are eating a large portion, then advise yourself that this meal probably contains 1,000 calories - half your day's allowance.

Counting calories is dull, but having a fair idea of the calorie content of your meals is handy. It allows you to develop useful rules of thumb when you are seriously trying to control your eating.

What is a portion? Well, portions have certainly got bigger over the last decade or so. A Beefeater restaurant steak plate from the 1960s (seen in an antiques shop recently) looked really small to me. We have got used to eating off huge plates. We eat out much more than a generation ago, and we load our plates at the buffet to get our money's worth. All this makes it harder for us to assess a portion so we find it hard to manage our weight.

And when we buy a pre-pack meal from the supermarket, what looks like a meal for one, on close reading of the package, is a meal for two. On the plate it looks like a portion for one, (or maybe 1 and a tiny visitor). I am starting to think that it is calories for two but quantity for one. Look at an interesting portion control discussion here.

The King Size 84g Mars Bar was phased out following a House of Commons report, which showed that a Snickers bar had more calories than a full steak meal. It was replaced by the Mars Duo - two bars now at 91g (about 400 calories - equivalent to a plate of chicken, potatoes and veg). Research shows that once a pack is opened we eat it, so the unintended consequence of the House of Commons report is that we eat even more! For those with a sweet tooth and a desire to lose weight, buy fun packs. One little bar is a portion.

If you hold onto the idea that one formal meal is round about 500 calories, then when you read the calorie content of a sweetie bar or other snack, you can get an idea of the relative benefit of eating it. I was once given a delicious slice of chocolate cake - and was horrified to see that it contained 1,500 calories. A belt buster to be sure!