According to the U.S. National Institutes of Health (NIH), a blood glucose level below 70 mg/dL (3.9 mmol/L) at the time of symptoms followed by relief after eating confirms a diagnosis for reactive hypoglycemia. Signs and symptoms
Symptoms vary according to individuals hydration level and sensitivity to the rate and/or magnitude of decline of their blood glucose concentration.A crash is usually felt within four hours of heavy carbohydrate consumption. Along with the symptoms of hypoglycemia, symptoms of reactive hypoglycemia include:

The majority of these symptoms, often correlated with feelings of hunger, mimic the effect of inadequate sugar intake as the biology of a crash is similar in itself to the bodys response to low blood sugar levels following periods of glucose deficiency. Causes
The NIH states: "The causes of most cases of reactive hypoglycemia are still open to debate. Some researchers suggest that certain people may be more sensitive to the body’s normal release of the hormone epinephrine, which causes many of the symptoms of hypoglycemia. Others believe deficiencies in glucagon secretion might lead to reactive hypoglycemia.Several other hormones are responsible for modulating the bodys response to insulin, including cortisol, growth hormone and sex hormones. Untreated or under-treated hormonal disorders such as adrenal insufficiency (see also Addisons disease) or growth hormone deficiency can therefore sometimes cause insulin hypersensitivity, and reactive hypoglycemia. Stomach bypass surgery or hereditary fructose intolerance are believed to be causes, albeit uncommon, of reactive hypoglycemia.
The channels are transformed into a side channel, which is the difference between the two input channels, and a mid channel, the sum of the two input channels. In place of a mid channel, the left channel or the right channel may be encoded instead, which is sometimes more space efficient.Even though the reference encoder uses a single block size for the whole stream, FLAC allows the block size in samples to vary per block. Compression
The amount of compression is determined by various parameters, including the order of the linear prediction model and the block size. Regardless of the amount of compression, the original data can always be reconstructed perfectly. For users convenience, the reference implementation defines 9 compression levels, which are presets of the more technical parameters to the encoding algorithm. The levels are labeled from 0 to 8, with higher numbers resulting in a higher compression ratio, at the cost of compression speed. The meaning of each compression level varies by implementation.FLAC is optimized for decoding speed at the expense of encoding speed. A benchmark has shown that, while there is little variation in decoding speed as compression level increases, beyond the default compression level 5, the encoding process takes up considerably more time with little space saved compared to level 5. Comparison to other formats
FLAC is specifically designed for efficient packing of audio data, unlike general-purpose lossless algorithms such as DEFLATE, which are used in ZIP and gzip.