The late 1800s and early 1900s were notoriously terrible in UK and the literal shrinking and weakening of the population due to their diet is documented over time - and it was actually due to increasing trade, industrialization, and globalization. Beforehand things were much better. The expansion of available foods made things much worse.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2672390/
> The fall in nutritional standards between 1880 and 1900 was so marked that the generations were visibly and progressively shrinking. In 1883 the infantry were forced to lower the minimum height for recruits from 5ft 6 inches to 5ft 3 inches. This was because most new recruits were now coming from an urban background instead of the traditional rural background (the 1881 census showed that over three-quarters of the population now lived in towns and cities). Factors such as a lack of sunlight in urban slums (which led to rickets due to Vitamin D deficiency) had already reduced the height of young male volunteers. Lack of sunlight, however, could not have been the sole critical factor in the next height reduction, a mere 18 years later. By this time, clean air legislation had markedly improved urban sunlight levels; but unfortunately, the supposed ‘improvements’ in dietary intake resulting from imported foods had had time to take effect on the 16–18 year old cohort. It might be expected that the infantry would be able to raise the minimum height requirement back to 5ft. 6 inches. Instead, they were forced to reduce it still further, to a mere 5ft. British officers, who were from the middle and upper classes and not yet exposed to more than the occasional treats of canned produce, were far better fed in terms of their intake of fresh foods and were now on average a full head taller than their malnourished and sickly men.
Times of famine were not extraordinarily rare. But I'd be very skeptical of the numbers you're providing. Famines where a lot of people start dying become revolutions and migrations. The Irish Potato Famine was a very exceptional famine in terms of numbers - but it wasn't that 25% of the population died, it's that 25% of the population died or left - there were about even numbers for both. The situation was also greatly worsened by the political situation, which did have major consequent political effects. Large famines are easier to track because of this.
I'm extremely skeptical of your numbers in general. Certainly people always starved: urbanites and social outcasts were at higher risk. What marginal increase are you declaring a famine? Even the 'severe' famine periodicity you mention seems very hard to support among any population groups and historical periods I know about. It's probably true in periods of extreme upset, but not in normal times, and in most stable societies food surpluses were stockpiled and preserved to hedge against such things.