I wanted to tell you all this anecdotal.
My aunt is in her 60s. Has been overweight and following weightwatchers or similar HER WHOLE ADULT LIFE. On these weight loss plans she has lost 2 lbs, gained 1 lbs etc etc providing she sticks to it v carefully she does lose but v v slowly and the minute she stops restricting calories etc weight piles back on. She has always eaten a lot of fruit - including mangos/ pineapple / strawberries / bananas / grapses - probably 3-4 portions a day. Plus breakfast cereal, can't remember which one, something like fruit and fibre etc. And of course rice cakes, ryvita, pasta (but calorie controlled portions).
Anyway she asked me a few months ago how did I lose the weight, and I told her. Her first reaction was I am not doing faddy low carb. Anyway she eventually agreed - she is NOT doing ketosis - but has cut out grains and potatoes. She is eating some dairy (small amounts of cottage cheese) and apple or pear per day, and no restriction on carby veg like carrots. Any I just spoke to her - for the first time in more than 10 years she is under 12 and a half stone (from I think around 15 stone which was a lot as she is short) and unlike previous diets the weight has come of 2lbs a week consistently.
She has loads of willpower and is v motivated but slightly 
at all the advice she was given by dieticians etc low fat high carb and that "fruit was free", because these diets have not worked for her.
Anyway - wanted to post - firstly to show that anyone who doesn't know what they are doing wrong probably is eating too much fruit, and secondly, to show that ketosis diet not necessary essential to efficient weight loss.