Need to fit into that little black number or your brand-new pair of skinny jeans? Certain foods can help you on the road to a skinnier you.

Just remember that many other factors contribute to a healthy weight. Diet, and foods that could play a role in terms of weight loss, won’t do much if you're inactive or if the rest of your diet consists of nutrient-poor, kilojoule-dense fast foods. Like all things in life, it's about balance.

Also note that some of the research results listed below need to be confirmed by further studies and that firm conclusions can't be made as yet…

Soup


Having a bowl of soup before your main meal could help you lose weight. But research studies contradict each other in the type of soup that's best.

Researchers from Penn State University found that low-energy soup made from chicken stock and vegetables lowered participants' total energy intake during meals by 20%. On the other hand, researchers from Duke University found that eating a fatty broth such as chicken soup before dinner also reduced the total amount of food consumed by 20%.

In a more recent study, scientists measured the different satiety levels after study participants first each had a solid meal, then a chunky soup and, lastly, a smooth soup. Interestingly, the smooth soup had the highest satiety rating, making the participants feel fuller for longer.

The bottom line, it seems, is to have soup for starters if you're trying to lose weight. Skip the cream-based soups and go for smooth, nutrient-rich chicken or vegetable broths instead. This way, you'll also up your daily intake of disease-fighting vitamins, minerals and antioxidants.

Dairy


A diet rich in dairy products has been linked to healthy weight management, but the topic remains controversial.

Some research has shown that the calcium in milk, yoghurt and cheese plays a key role in terms of reducing fat cells in the body. Other studies have indicated that the protein in dairy could increase satiety and aid weight loss, while certain enzymes could act synergistically with calcium to reduce fat levels.

It's important to note, however, that many cheeses and certain other dairy products have a high fat content and that excess consumption may actually lead to weight gain.

So, while more research is being done to test the weight-loss association, the general recommendation is to eat two to three portions of dairy products every day.

High-fibre foods


A diet high in fibre-rich foods such as fruit, vegetables, pulses, whole-grains and high-fibre cereals is associated with less weight gain, smaller weight circumference and lower body fat stores, according to a growing bank of research studies.

Fibre can be defined as complex carbohydrates that can't be digested or absorbed by the body. It's believed that because it provides bulk in the diet without adding kilojoules it has a positive effect in terms of weight management. Fibre-rich carbohydrate foods (e.g. seed bread) generally have a lower energy density than low-fibre carbohydrate foods (e.g. white bread).

Apart from possibly helping you to maintain a healthy weight, fibre also helps to keep the digestive system healthy and regular.

Nuts


A few nuts a day could help you maintain a healthy weight. Quite a few research studies show that nuts, a good source of healthy fats, may enhance a feeling of fullness.

One of these studies by a group of American researchers tested almonds' effect on weight loss by supplementing overweight women with two servings of almonds a day for ten weeks. The researchers found that there were no changes in energy intake or body weight in the almond-eating women, and came to the conclusion that the women found the almonds filling. This meant that they consumed fewer kilojoules at other meals.

But nuts have quite a high energy value. So, while they could have an important role in the diet – especially if they replace other fats – you should still keep an eye on your intake. Have a small handful of nuts no more than three times a week.

Spicy foods


Eating spicy foods leads to a process called "thermogenesis", or heat generation, in the body. This burns kilojoules, which can help to keep unwanted kilos in check.

Researchers from Maastricht University in Holland and Laval University in Quebec reviewed studies that looked at the effects of capsaicin, black pepper, ginger and mixed spices in terms of energy balance and thermogenesis.

The results seem to indicate that capsaicin, the compound that gives red chilli pepper its kick, leads to greater heat generation, which burns more kilojoules immediately after a meal. Black pepper seems to stimulate metabolism, while ginger also has thermogenic properties. And, like black pepper, mixed spice has a positive impact on metabolism.

But be warned: spicy foods could be dangerous, especially if you suffer from heartburn or a gastrointestinal tract disorder (for example, a peptic ulcer). If, however, you're given the all-clear by your doctor, there's no reason why you can't include more chilli, black pepper, ginger and spices in your diet.