Israeli authorities blockading the Gaza Strip in 2008 went so far as to calculate how many calories would be needed to avert a humanitarian disaster in the impoverished Palestinian territory, according to a newly declassified military document.

The military said Wednesday the guidelines were never implemented. However critics rejected the claim, saying the document was new evidence that Israel used food as a pressure tactic to try to force Gaza's Hamas rulers from power — a strategy that ultimately failed.

Israel maintained a strict blockade over Gaza from 2007-2010. During that time, Israel limited food supplies entering Gaza and maintained a baffling list of items that were banned or permitted as part of a broader effort to topple the violently anti-Israel Hamas by squeezing the economy.

In the January 2008 document, Israel determined how to ensure that Gazans eat 2,279 calories of food each day, a figure in line with World Health Organization guidelines.

It broke down the calorie allocation by various food groups, and in minute details. It said that males aged 11 to 50 required 316.05 grams of meat per day, and women in the same age group needed 190.47 grams of flour. The analysis also included adjustments for locally grown farm products as well as an assessment of the kinds of food imports that would be needed to sustain the population.

Israeli military spokesman Maj. Guy Inbar said these calculations were not meant to punish the people of Gaza. Instead, he described them as safeguards that helped to identify when goods were in short supply and a humanitarian crisis might be nearing.

"A mathematical formula was devised to identify food needs and avert a humanitarian crisis in Gaza," he said. Israel never used the calculation to restrict the flow of food to Gaza, he added.

Israel's Defense Ministry resisted years of attempts to release the guidelines, and consented only after an Israeli advocacy group, Gisha, won a Supreme Court order.

Gisha contends that Israel calculated the calorie needs for Gaza's population in order to restrict the quantities of goods and basic products it allowed in during the first three years after Hamas violently overran the territory.

The Israeli government imposed the blockade on Gaza after identifying it as a "hostile territory" in September 2007, three months after the takeover by Hamas, an armed, Iranian-backed group committed to Israel's destruction. Hamas has killed hundreds of Israelis in suicide bombings and other attacks and both Israel and the U.S. consider it a terrorist group.

In a government resolution on the blockade, Israel called for restrictions on the movement of civilians and goods in and out of the territory and to reduce the supply of fuel and electricity. The resolution, which noted repeated rocket attacks launched from Gaza, said Israel would strive "to avoid a humanitarian crisis."

Critics say the policy amounted to collective punishment of Gaza's already impoverished population of more than 1.5 million.

"The official goal of the policy was to wage 'economic warfare' which would paralyze Gaza's economy and, according to the Defense Ministry, create pressure on the Hamas government," Gisha said in a release Wednesday.

Israel controls the only official cargo crossings into Gaza, and greatly limited the flow of goods into the territory following the Hamas takeover. Israeli officials have said the flow of goods was often limited because of frequent Palestinian attacks on the crossings.

As part of its policy, Israel used odd, secret guidelines to differentiate between humanitarian necessities and nonessential luxuries. The result was that military bureaucrats enforcing the blockade allowed frozen salmon and low-fat yogurt into the Hamas-ruled territory, but not cilantro or instant coffee.

Gisha's director, Sari Bashi, said official military documents from that period indicate that the Israeli guidelines on calorie intake were in fact the basis of policy.

For example, the guidelines recommend allowing 300 calves into Gaza each week to fulfill the territory's meat needs. In a September 2008 court case, the government rejected a request by an importer to bring more calves into Gaza, saying 300 animals were sufficient, using an identical figure from the guidelines.

"Whether or not the document was a draft, it reflects the calculations that were used to set the policy," Bashi said. "The policy clearly restricted food."

In a U.S. diplomatic cable released by Wikileaks last year, American diplomats quoted their Israeli colleagues as saying the blockade was meant to push the area's economy "to the brink of collapse."

The embargo crippled Gaza's economy and wiped out tens of thousands of jobs by banning raw materials and suffocating trade. Gaza also frequently suffered from shortages of basic consumer goods.

Hamas mitigated ithe blockade's effect by building a network of underground tunnels to bring in food, weapons and other contraband from Egypt, at inflated prices.

Despite the shortages and hardship, at no point did observers identify a nutritional crisis developing in the territory, whose residents rely overwhelmingly on international food aid. Hamas remains firmly in control of Gaza.

In Gaza, Hamas spokesman Fawzi Barhoum said the document was "evidence that the Gaza blockade was planned and the target was not Hamas or the government as the occupation always claimed. This blockade targeted all human beings. ... This document should be used to try the occupation for their crimes against the humanity in Gaza."

Israel's blockade was suddenly forced into the international spotlight after Israeli naval commandoes carried out a deadly raid on a Gaza-bound international flotilla that sought to breach the embargo in May 2010.

Under heavy international pressure, Israel significantly eased the land blockade, allowing consumer goods to move into Gaza freely.

Construction materials are still largely barred from entering, on the ground that Gaza militants could use items such as pipes and concrete to attack Israel. A naval blockade also remains in effect, which Israel says is necessary to prevent weapons smuggling at sea. Exports remain heavily restricted.

"Israel never saw the people of Gaza as our enemy," said Israeli government spokesman Mark Regev. "On the contrary, we saw them as victims of the extremist Hamas regime, a regime that places its very radical agenda above and beyond the interest of the people of Gaza."