Too much of the wrong foods
Reason
Our body responds to different foods in different ways. When we consume sugar and carbohydrates insulin levels quickly rise to transport the glucose (blood sugar) produced from these foods to the muscles ready to be used as energy. Any excess gets sent away and stored as fat.
Solution
Try to choose foods that are richer in protein and good fats as these will help to stabilise glucose and insulin levels and will assist in keeping you fuller for longer. Limiting sugar and alcohol and reducing carbohydrate will help to reduce excess energy stores in the muscles so the body will then have to start to burn fat when energy is needed.
Too much of the right foods
Reason
A friend of mine recently came to me in despair as she had been struggling to lose weight despite having not touched chocolate for weeks. It turned out that she had been endlessly snacking in-between meals on healthier foods like nuts, nut butter, hummus, and lots of fruit. Collectively these foods were adding around 1000 calories to her daily intake.
Solution
Many of us are fooled into thinking that only white carbs, sugar and junk food are fattening and that we can eat health foods in abundance. My advice would be to enjoy these foods and their benefits, but if you consume endless supplies you may struggle to see results. In addition to this be aware that 'organic' foods or those labelled as 'natural' can still be high in sugar and in calories so always check out the label..
Learn to understand portion size. Here's a serving of muesli I measured out which you may find surprising.
Food Amnesia
Reason
When you recall what you have eaten in a day do you remember everything? Did you count that extra handful of nuts, or finishing off of your kids lunch, the biscuit that was given on the side of your latte? How about the latte itself? What about when you prepare a meal? How many of the ingredients do you taste during the process?
Solution
Mindless eating and 'picking' mounts up more than you think. As an experiment try recording absolutely everything you eat and everything you drink. Don't miss out a single bite. Pay extra attention to the in-betweeny foods as it is highly likely that these will be the guilty parties. This will help bring to attention any forgotten foods. See if you can go without those extra nibbles.
The wrong kind of exercise
Here are two possible reasons why exercise is not working for you.
Reason
You aren't pushing yourself. I am sorry to say, a few ab crunches and some half hearted bicep curls will do absolutely nothing in helping you fit into your old jeans again. Exercise must feel effortful.
Solution
If weight loss is your goal and exercise is the plan then you must push yourself past what you can comfortably do. In addition to this don't limit movement to when you exercise. Move as much as you can out side of the gym. Movement uses energy and also helps to increase the metabolism. Both of these factors can help weight loss. Move as much as possible. Walk up a hill, clean the house, dig the garden, dance. anything that gets you off of your backside.
Reason
Your diet is not supporting your weight loss goals. Just because you have been to the gym this doesn't mean that what you eat doesn't count. If you eat too much, irrespective of whether you exercise or not, you will struggle to see results. I often hear people say they are overweight because they don't exercise enough yet their diet says something else.
Solution
Your diet and exercise plan should work together to support your goals. Take an honest look at your diet and address any further changes that need to be made. Construct your diet to compliment your exercise plan and to support results in the gym.
Inconsistency
Reason
You work out, eat well, keep hydrated, you're the epitome of discipline, in total control. However when your routine is broken you are a different beast. You feel like you have been set free, beer in one hand and Doritos in the other. It's actually fine, you can enjoy these foods, they should simply just make up a small percentage of your overall diet.
Solution
The answer is BALANCE. This may not just mean reigning it in at the weekend. If your weekday routine leaves you craving forbidden foods then you are never going to be able to control yourself when faced with temptation. Look at changing your diet so you keep control and enjoy food every day of the week.