PSA for viewers on behalf of the soon-to-be million-dollar margarine (high trans-fats, fake butter) industry, with a close-up on a package of margarine and a polyunsaturated fats speech by Mrs Brown, which started the low-fat foods craze.
Mrs. Brown lectures Martin about counting calories, suggesting he cut out jam & butter. But she then brings him an entire tray full of chocolate brownies, over a dozen of them, and he eats most of them in a single sitting. Each brownie would contain far more calories than a little jam or butter, so it makes no sense that Mrs. Brown, who has been encouraging him to cut calories, would bring him a "snack" that, by itself, contains a full day's worth of calories.
Martin tells Tim that martians must be on a "poly-saturated" diet, instead of the polyunsaturated that Mrs. Brown recommended. So must humans! Saturated (animal) fats are necessary for many metabolic processes, including good cholesterol balance and proper brain function. The margarine Mrs. Brown advocates is synthetic, which turns into trans-fats that causes many health problems. Sadly, the vilification of saturated fats has gone on since circa this show's era (1964), well into the 2000's and beyond. The information that our ancestors were right to eat a diet high in animal saturated fats is slow to reach the masses with all the disinformation promoted by the corn, grains and agricultural industry, as well as the fat-free and margarine food industry and---in the 2020's--- by the synthetic meat industry and their fervent pushers, such as vegans. Their bottom line is the dollar, not the health and well-being of their willfully misguided consumers.