Lauer J B, Reed G W, Hill J O
Department of Psychology, Indiana University-Purdue University at Indianapolis, 46202-3275, USA.
Obes Res. 1999 Mar;7(2):215-22. doi: 10.1002/j.1550-8528.1999.tb00704.x.
Although the majority of evidence in rodents does not support the view that weight cycling (consisting of bouts of food restriction and refeeding) promotes obesity, the effects of weight cycling on body weight regulation remain controversial. We have previously demonstrated that some rats within a strain are more susceptible to develop obesity than others when given free access to a high-fat diet. In this study, we tested the hypothesis that rats most susceptible to weight gain on a high-fat diet would also be most susceptible to weight gain as a consequence of weight cycling.
Rats were provided a low-fat diet (12% corn oil) for 2 weeks, then given a high-fat diet (45% corn oil) for 2 weeks to identify those most (obesity prone) and least (obesity resistant) susceptible to weight gain. Half of each group was then subjected to three 30-day cycles of food restriction (10 days) and refeeding (20 days) [weight cycler (WC) rats]. The other half were allowed free access to the high-fat diet [control (CO) rats]. All rats were then followed for an additional 10 weeks, with free access to the high-fat diet.
When considering the entire 160 days of the study, we found no evidence that WC rats relative to CO rats had increased body weight, increased body fat content, or elevated energy efficiency. We found no evidence that rats most prone to dietary obesity were also prone to weight gain after weight cycling. During the weight cycling phase (days 1 to 90), weight cycled groups consumed less energy and gained less weight than controls. During the follow-up phase, WC and CO rats did not differ significantly in weight gain or energy intake.
In this study, weight cycling did not exacerbate the obesity produced by high-fat diet feeding.
尽管啮齿动物的大多数证据并不支持体重循环（由节食和再喂养周期组成）会促进肥胖这一观点，但体重循环对体重调节的影响仍存在争议。我们之前已经证明，当自由摄取高脂饮食时，同一品系的一些大鼠比其他大鼠更容易肥胖。在本研究中，我们检验了这样一个假设，即高脂饮食时最易体重增加的大鼠在经历体重循环后也最易体重增加。
给大鼠提供低脂饮食（12%玉米油）2周，然后给予高脂饮食（45%玉米油）2周，以确定那些最易（肥胖倾向）和最不易（抗肥胖）体重增加的大鼠。然后每组的一半大鼠经历三个30天的节食（10天）和再喂养（20天）周期[体重循环（WC）大鼠]。另一半大鼠自由摄取高脂饮食[对照（CO）大鼠]。然后让所有大鼠再自由摄取高脂饮食10周。
在考虑整个160天的研究时，我们没有发现证据表明与CO大鼠相比，WC大鼠体重增加、体脂含量增加或能量效率提高。我们没有发现证据表明最易因饮食导致肥胖的大鼠在体重循环后也易体重增加。在体重循环阶段（第1至90天），体重循环组比对照组消耗的能量更少，体重增加也更少。在随访阶段，WC大鼠和CO大鼠在体重增加或能量摄入方面没有显著差异。
在本研究中，体重循环并没有加剧高脂饮食喂养所导致的肥胖。
