Eating too many or not enough calories
So let's address the not eating enough calories first as this can be extremely counterproductive to your weight loss efforts, you don't need to be in an excessive calorie deficit to achieve this weight loss. It has been proven that eating less than 1000 calories per day can cause muscle loss and cause your metabolism to slow.
You don't need to be in the generic 3500 calorie deficit per week to lose 1lb per week either as everyone's body is different so the exact figure will differ from person to person.
You're eating healthy but too much, be aware of portion sizes and calorie dense food such as avocados and nuts.
When it comes down to it to lose weight you have to be burning more calories than you are consuming, it's as simple as that. Try using a food tracking app on your phone, this was a real eye opener for me, to see exactly what was in the food I was eating.
Not lifting weights and just sticking to cardio
Lifting weights is so important whilst you're trying to lose weight. This type of training increases muscle mass and therefore increases your metabolic rate. It's great for strengthening your joints and burning fat especially around your stomach. Females don't worry you won't get big and bulky as we don't produce enough testosterone but you'll burn fat and slim down and get toned.
Focussing on just the scales
It's a marathon not a race, Rome wasn't built in a day, remember these whilst on your weight loss journey. Yes it's frustrating when your not seeing those numbers on the scales move in your favour even though you've cut this and that out of diet and your religiously going to the gym, but fear not it's completely normal. The scales are just one measure of your progress and don't tell the whole story, please don't get stuck on what they say as it can become so unhealthy and I know as I've been there.
You're weight can fluctuate by 4lb either way throughout the day, you can retain water this is especially true in women due to oestrogen levels and hormone changes. You could be holding on to water but losing fat mass, you could be building muscle and burning fat so the scales don't alter. This can happen in people new to weight training and is very common, for instance I dropped 5 dress sizes but only lost around 2 stone.
Choosing low fat and diet foods
Advertised as good food choices but lets face it, if they are removing the natural fats what are they replacing them with? These products are often the worst types of processed foods, yes processed.
These foods are often loaded with sugar to make them taste better and because the natural fats have been removed the won't keep you full leaving you feeling hungrier.
You don't eat enough protein
Eating enough protein is so important whilst your losing weight, It reduces appetite as it takes longer for protein to be digested by the body making you feel fuller for longer. It increases your metabolic rate because it takes energy to be broken down by the body, and is the building blocks for muscle repair. You should be eating protein for every meal and around 0.8-1g of protein per pound of body weight.