A lack of sleep may be hindering your weight-loss goals. Sleep deprivation slows your metabolism and affects the hunger hormones leptin and ghrelin.

Leptin tells your brain to stop eating, whereas ghrelin, produced in the stomach, stimulates hunger. Research suggests inadequate sleep is associated with low levels of leptin, high levels of ghrelin and weight gain.

Solution: Turn off your phone and laptop. Instead, focus on good sleep hygiene: get to bed early, make sure your room is dark and cool and avoid all drugs including cigarettes, alcohol and sleeping pills.

Hidden sugars are everywhere. The biggest culprits include muesli bars, breakfast cereals, sports drinks, sauces and spreads – even certain peanut butter brands contain sugar. So what's the big deal? Added sugars are now considered to be more damaging than dietary fat to your weight and overall health, contributing to conditions including dental decay, diabetes, heart disease and obesity.

Solution: Read labels and avoid products with high amounts of added sugar. It may be listed as corn syrup, sucrose, malt, glucose, molasses, fructose, maltose or fruit juice concentrate.

There is no question that portions need to be smaller in order to lose weight. However, we have become so obsessed with calorie control that we often overlook the most important aspect of food – the nutrients.

Solution: Think quality. Don't just focus on the calories. Instead, choose nutrient-dense foods and nourish your body with the vitamins, minerals and antioxidants found in fruit, vegetables and wholefoods.

Also known as xenoestrogens, these are synthetic chemicals found in plastics, fertilisers, detergents and cosmetics. While the effects of xenoestrogens on the body are still being studied, it is believed they can mimic the biological hormone oestrogen. Excess oestrogen can result in weight gain in both men and women.

Solution: Ditch plastic drink bottles and containers and opt for glass instead. Buy organic products if possible.

Watching the Kardashians, doing sedentary jobs and stalking old flames on Facebook is a far cry from our hunter-gatherer ancestors. You may think you're too busy to exercise, but the reality is we are meant to move.

Solution: Fidget. You may laugh, but this is known as NEAT non-exercise activity thermogenesis). Research suggests those who fidget burn hundreds of extra calories throughout the day. Fidgeting includes crossing or uncrossing the legs, stretching, standing up often or maintaining a good posture. Aim to move every 30 minutes to bump your body out of hibernation mode.

The combination of busy lifestyles and fast food at our fingertips has resulted in less food preparation in the home. Grabbing breakfast on the go or takeaway for dinner is not good for your waistline.

Solution: Set a goal to attempt a new, healthy 20-minute meal each week. Whenever you make a meal, make extra and freeze portions for those days you don't have time to cook.

Hormone conditions such as hypothyroidism, polycystic ovarian syndrome and insulin resistance can cause weight gain and make it hard to lose weight.

Solution: Talk to your GP and get tested. If you have one of these conditions, diet may help. Exclude refined carbohydrates and increase good-quality protein, vegetables, seaweed and essential fatty acids.

For decades dietary fat was considered the enemy when it came to weight loss. But interestingly, since the introduction of low-fat products we have seen an increase in obesity around the world.

Solution: Scrap your negative view on fat and include a small amount of "good" fats in each meal. The essential fatty acids in flaxseed oil, oily fish, nuts and seeds not only help you feel full but also facilitate fat breakdown.

Marketing of processed foods can be confusing. A package may read "source of calcium" or "no artificial colours" but still be packed with sugar.

Solution: Read the ingredient list. If sugar is in the first three ingredients or it has chemicals you haven't heard of, don't buy it.

The set point theory says our body is programmed to be a certain weight and fights to stay there. This may explain why calorie restriction alone doesn't produce long-term weight loss.

Solution: Steady weight loss through a balanced diet and exercise is the only proven way to lower your set point. Aim for a loss of a kilo a week and give your body time to adjust.