Around one in five of us start a new diet every few weeks, and January just happens to be peak season for all those weight-loss resolutions. But, for every 100 people who begin a diet, only five will achieve their weight-loss goals. Everyone else will be calorie-counting, detoxing, low carbing, blood typing, going paleo and suffering, to absolutely no avail.

Why do so many diets fail? Partly, of course, because many are ridiculous. But there's an increasing body of research that suggests that different factors are at play. Scientists have discovered that we all gain weight for different reasons -- and those reasons are to do with our psychology, our motivations and the way we handle stress.

The good news is, you can use this information to design a diet that is more suited to you as an individual. Here's how the different personality types could benefit from different approaches to losing weight and getting healthy.

Extrovert vs. Introvert

Extroverts are creatures of impulse. They like to choose foods because they're attractive, exciting, comforting or simply there. Naturally sociable, they tend to eat in response to social situations even if they are not hungry. And since they are highly responsive to outside stimuli, extroverts are more likely to binge at buffets simply because all that food is in front of them, and it looks great.

Introverts, by contrast, are more cautious about what they eat. They generally will weigh up the risks of choosing the healthy option versus the not-so-healthy option in terms of the long-term effects on their weight loss regime. They are also more likely to respond to internal hunger cues and eat only when they are hungry.

Matching your personality to your diet: One study reported in the Journal of Personality and Social Psychology suggests that impulsivity is the strongest predictor of obesity. By that reasoning, extroverts are the most likely to gain weight over time. The key, then, is to minimize temptation -- extroverts really should banish the brownies and keep only healthy snacks like fruits and vegetables in the kitchen. There is also evidence to suggest that weight loss done in a group setting may be more effective for extroverts than for introverts.

Introverts tend to be more private and are likely to prefer the anonymous nature of an online diet program. They are also self-disciplined and work well within a rules-based system where they can make a weight-loss contract with themselves.

Sensor vs. Intuitive

Sensors live in the here-and-now and love facts and routines. In many ways, they are the best type of dieters out there, since they will thrive on details like calories, carbs and fat grams. To stay the course exactly, Sensors typically need to follow strict eating rules; when left to make too many decisions, they have a tendency to overeat.

For Intuitives, "the diet begins on Monday." That's because they live in the future and are more likely to focus on the big picture than something as mundane as food. Routine will probably kill their weight-loss efforts, since they're too rebellious to count calories or say "no" to certain foods just because someone else says they are sinful. This means that Intuitives can be pretty unmindful about what they eat --but if they don't engage their brain, they may end up eating the entire chocolate cake instead of just one slice.

Matching your personality to your diet: Sensors will love traditional calorie-counting or prescriptive diets where they are given a detailed list of what foods to eat and when. They are also pretty good at sticking to an exercise regime, especially if they are encouraged to treat exercise as a special appointment and mark it on their schedule. Intuitives, by contrast, need flexibility. They may be better having a number of healthy meal choices they can cycle through weekly, with enough flexibility to stop them from getting bored.

Thinking vs. Feeling

Thinkers use their superior analytical skills to weigh up the pros and cons of a healthy eating plan before deciding to take action. Generally, they are good with any type of regime, as long as they see the logic in the approach. The biggest problem for Thinkers is information overload. For example, a Thinker may opt for a low-carb plan and enjoy some measure of success. But if she reads an article about the benefits of whole grains, she may do a diet-180 and add carbs to her plan -- and the whole system could spiral out of control.

Feelers are much more personal, compassionate, and empathetic. They crave connections with the people around them and will do everything in their power to avoid conflict. This can jeopardize weight-loss efforts. For example, if everyone is sharing a cake at a birthday celebration, a Feeler will feel obligated to have a piece so she can celebrate with the group, even if she is not hungry. When a Feeler tries to go it alone, she may come slightly off the rails, as if her weight loss decisions are out of her immediate control.

Matching your personality to your diet: Feelers do best with a holistic approach to weight management, that is, a plan that accommodates their physical, social and emotional needs. The perfect weight loss plan involves plenty of support from family members and other people who've been there -- weight loss programs that meet weekly or a regular exercise class will give Feelers the support and camaraderie they need. Thinkers need far less support in achieving their weight-loss goals. However, they may need help to see that good health is the real goal, and not the relentless pursuit of information.

Judging vs. Perceiving

Judgers are action-oriented people. Once they've opted to go for a weight loss plan, they generally will press ahead with the speed and efficiency of a German passenger train. They usually have great success at achieving their goals, especially in the early days of a plan. However, Judgers thrive on rapid closure and may abandon a plan if it is taking too long to see results.

Perceivers are more spontaneous and dislike following rigid rules or making lists. They are very responsive, so the moment may get interrupted if something more pressing or enjoyable comes along. Like Intuitives, Perceivers live by the motto "I can always start my diet tomorrow." They are the type most likely to abandon a plan if there is not enough variety of foods to choose from.

Matching your personality to your diet: Judgers are good with organization and structure and will thrive with any kind of detailed eating and fitness plan. Keeping a food diary is a great approach as it allows Judgers to recognize exactly what they're eating each day and systematically adjust their intake to keep up the momentum. Perceivers, by contrast, will go crazy if they have to write everything down. They probably will need external support to follow through with a weight-loss project; many will find success by ditching the diet books entirely and following an intuitive eating plan.

Your personality, your diet plan

The objective isn't to follow the latest fad diet or set extreme weight-loss goals, it's finding a way of eating that works with your personality rather than against it. Maintaining a healthy weight probably won't be easy, but at least you won't be setting yourself up for failure before you even begin. Bon appetite!