This regulation is relaxed in response to caloric restriction and low blood glucose. Mild intoxication may remain asymptomatic and require only fluid restriction. Various methods of gastric bypass or gastric restriction surgery are used to treat morbid obesity. There is no maximum age restriction. The Directive lists several substances subject to restriction. The restriction to stocks as a benchmark is somewhat arbitrary. Some attempts is to lose the stricter restriction of the function. This may be accomplished by means of PCR, restriction fragment analysis and/or DNA sequencing. It involves the use of restriction enzymes. This could present an arbitrage opportunity in the absence of any restriction on reselling. This was limited, however, by an undocumented restriction on supported codecs. Sexual activity between women was never subject to the same legal restriction. The same group investigated protein restriction and neomycin. This makes the length restriction more questionable. Treatment includes a healthy diet, salt restriction, and exercise.