I think my family may have been very different from some of yours back in the 1960s and 1970s. My parents were children during the war and when rationing finally ended and you could get unlimited sweet stuff my Dad in particular was delighted, having a very sweet tooth. My Mum was never without a packet of sweets in her handbag and would often hand out boiled sweets or Mint Imperials to while away the time on a short bus journey. We always had sweets in at home and as a Scottish family our diet was very heavy indeed on saturated fat, salt, white sugar and white flour. We had sliced white bread and butter, with jam or lemon curd if we wanted it, followed by cake, chocolate biscuits or similar every evening as part of our high tea, following a substantial cooked main course. Portions were generous and we could eat as much as we wanted. Fortunately our diet was also pretty varied in other ways.
We had fish fairly often and we had plenty of soups, often incorporating barley, peas, beans or lentils. We had a decent range of vegetables and in the summer we often had salad (traditional British salad - leaves from a round lettuce, sliced cucumber, sliced tomato, pickled beetroot, pickled onions, salad cream). Tinned fruit was a staple. Fresh fruit was considered expensive and my brother and I were expected to share an apple or an orange between us. Brilliant reverse psychology, albeit unintended, because I grew up regarding fruit as a great treat and sometimes used my pocket money to buy an orange to have all to myself, because I never needed to buy sweets.
My Mum made liberal use of convenience foods as soon as they became available. All the people claiming that food in the 70s was additive-free - not in our house it wasn't! Angel Delight and all sorts of other packet mixes were used. Arctic roll, ready-made trifle sponges, lemon meringue pie mix, ready-made flan cases (sponge or pastry), meringue cases, ice cream made of god knows what (it looked awful when melted, let's put it that way) - and that's just the sweet stuff. This was purely to save time. Mum was and is a very good cook, but when she was working full-time, catching up on the housework and the laundry was her priority outside work, not cooking.
Oddly enough my brother and I were not overweight as children. We weren't skinny, but we certainly weren't fat. I really can only explain this by saying we took a lot more exercise then and burned a lot more calories keeping warm (no central heating till well into the 1970s).
Possibly worth mentioning too that in spite of the above diet, my Dad lived till 89 and my Mum is still with us at nearly 92.